I would be very grateful for some advice on this. We bought a house from a developer two years ago, the house included what we thought was a useful outhouse that could become a mancave at some point... simple construction, built with breeze blocks, but when we read up on the planning permission we realised it was a way of getting round planning permission for them as our car parking space is on top of it (there were protected trees in the way of the space that was on the original plans). I know it sounds eccentric that we park on top of it... that part of our garden is a storey below street level.

We've had constant damp patches ever since we moved in. The parking space is on a slope and we seem to get all the rain seeping into side of the outhouse that is at the lowest point. Everything in there is has mould on it and there is constant condensation inside the glass door. I have an electrician here today installing a fan, he has noticed there are two layers of the breeze blocks in the wall with a gap in between and he can see the bricks are damp in between the gap.

Next to our car parking space there is a narrow gutter leading to a drainpipe, that is also very narrow, but I can also see dark patches of damp and mould all over the ceiling of the outhouse (which is wooden struts supporting plywood and then whatever the builders put above that.

We did manage to get the developer to put some leading around the edge of the car parking paving, but it hasn't had any affect on the damp as far as I can see. Our neighbour shares the other half of this outhouse (he parks his car next to us) and he says there is no point in pursuing the developer, we just have to work out our own fixes.

If anyone has some advice I would be really grateful, I'm worried the outhouse will collapse under the weight of our cars as much as anything!

On Tuesday, 21 January 2020 15:03:15 UTC, Anna Bonaddio wrote:

I would be very grateful for some advice on this. We bought a house from a developer two years ago, the house included what we thought was a useful outhouse that could become a mancave at some point... simple construction, built with breeze blocks, but when we read up on the planning permission we realised it was a way of getting round planning permission for them as our car parking space is on top of it (there were protected trees in the way of the space that was on the original plans). I know it sounds eccentric that we park on top of it... that part of our garden is a storey below street level.

We've had constant damp patches ever since we moved in. The parking space is on a slope and we seem to get all the rain seeping into side of the outhouse that is at the lowest point. Everything in there is has mould on it and there is constant condensation inside the glass door. I have an electrician here today installing a fan, he has noticed there are two layers of the breeze blocks in the wall with a gap in between and he can see the bricks are damp in between the gap.

Next to our car parking space there is a narrow gutter leading to a drainpipe, that is also very narrow, but I can also see dark patches of damp and mould all over the ceiling of the outhouse (which is wooden struts supporting plywood and then whatever the builders put above that.

We did manage to get the developer to put some leading around the edge of the car parking paving, but it hasn't had any affect on the damp as far as I can see. Our neighbour shares the other half of this outhouse (he parks his car next to us) and he says there is no point in pursuing the developer, we just have to work out our own fixes.

If anyone has some advice I would be really grateful, I'm worried the outhouse will collapse under the weight of our cars as much as anything!

I can't help thinking there's just not enough info here. As a short term measure I'd plug a dehumidifier in. A fan I would not expect to keep on top of it or prevent further damage, and the damage from mould can be extensive and very expensive.

I'd suggest posting some pics of the outside so we can see what the relationship is between the outhouse & ground levels, slopes, water drainage etc. Maybe some pics showing construction details on the outhouse too. I'll admit to being surprised that, IIUC, you're parking your car on a plywood roof. Details might help, that might be a problem area in a couple of ways.


NT

What do the local council building control say about what they did, if its
unsafe I'd have thought they could force them to redo all of these stupid
designs, but you may have to lose your car parking spot at least for a time.
Brian

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This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

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Note this Signature is meaningless.!
wrote in message
...
On Tuesday, 21 January 2020 15:03:15 UTC, Anna Bonaddio wrote:

I would be very grateful for some advice on this. We bought a house from
a developer two years ago, the house included what we thought was a useful
outhouse that could become a mancave at some point... simple construction,
built with breeze blocks, but when we read up on the planning permission
we realised it was a way of getting round planning permission for them as
our car parking space is on top of it (there were protected trees in the
way of the space that was on the original plans). I know it sounds
eccentric that we park on top of it... that part of our garden is a storey
below street level.

We've had constant damp patches ever since we moved in. The parking space
is on a slope and we seem to get all the rain seeping into side of the
outhouse that is at the lowest point. Everything in there is has mould on
it and there is constant condensation inside the glass door. I have an
electrician here today installing a fan, he has noticed there are two
layers of the breeze blocks in the wall with a gap in between and he can
see the bricks are damp in between the gap.

Next to our car parking space there is a narrow gutter leading to a
drainpipe, that is also very narrow, but I can also see dark patches of
damp and mould all over the ceiling of the outhouse (which is wooden
struts supporting plywood and then whatever the builders put above that.

We did manage to get the developer to put some leading around the edge of
the car parking paving, but it hasn't had any affect on the damp as far as
I can see. Our neighbour shares the other half of this outhouse (he parks
his car next to us) and he says there is no point in pursuing the
developer, we just have to work out our own fixes.

If anyone has some advice I would be really grateful, I'm worried the
outhouse will collapse under the weight of our cars as much as anything!

I can't help thinking there's just not enough info here. As a short term
measure I'd plug a dehumidifier in. A fan I would not expect to keep on top
of it or prevent further damage, and the damage from mould can be extensive
and very expensive.

I'd suggest posting some pics of the outside so we can see what the
relationship is between the outhouse & ground levels, slopes, water drainage
etc. Maybe some pics showing construction details on the outhouse too. I'll
admit to being surprised that, IIUC, you're parking your car on a plywood
roof. Details might help, that might be a problem area in a couple of ways.


NT

On 21/01/2020 19:20, wrote:
On Tuesday, 21 January 2020 15:03:15 UTC, Anna Bonaddio wrote:

I would be very grateful for some advice on this. We bought a house from a developer two years ago, the house included what we thought was a useful outhouse that could become a mancave at some point... simple construction, built with breeze blocks, but when we read up on the planning permission we realised it was a way of getting round planning permission for them as our car parking space is on top of it (there were protected trees in the way of the space that was on the original plans). I know it sounds eccentric that we park on top of it... that part of our garden is a storey below street level.

We've had constant damp patches ever since we moved in. The parking space is on a slope and we seem to get all the rain seeping into side of the outhouse that is at the lowest point. Everything in there is has mould on it and there is constant condensation inside the glass door. I have an electrician here today installing a fan, he has noticed there are two layers of the breeze blocks in the wall with a gap in between and he can see the bricks are damp in between the gap.

Next to our car parking space there is a narrow gutter leading to a drainpipe, that is also very narrow, but I can also see dark patches of damp and mould all over the ceiling of the outhouse (which is wooden struts supporting plywood and then whatever the builders put above that.

We did manage to get the developer to put some leading around the edge of the car parking paving, but it hasn't had any affect on the damp as far as I can see. Our neighbour shares the other half of this outhouse (he parks his car next to us) and he says there is no point in pursuing the developer, we just have to work out our own fixes.

If anyone has some advice I would be really grateful, I'm worried the outhouse will collapse under the weight of our cars as much as anything!

I can't help thinking there's just not enough info here. As a short term measure I'd plug a dehumidifier in. A fan I would not expect to keep on top of it or prevent further damage, and the damage from mould can be extensive and very expensive.

I'd suggest posting some pics of the outside so we can see what the relationship is between the outhouse & ground levels, slopes, water drainage etc. Maybe some pics showing construction details on the outhouse too. I'll admit to being surprised that, IIUC, you're parking your car on a plywood roof. Details might help, that might be a problem area in a couple of ways.


NT

+1.

Surely not on a plywood roof. That would be evident from inside. At the
least I would expect reinforced concrete beams, or perhaps a reinforced
concrete slab ideally supported on RSJs.

Anna Bonaddio wrote:
I would be very grateful for some advice on this. We bought a house from
a developer two years ago, the house included what we thought was a
useful outhouse that could become a mancave at some point... simple
construction, built with breeze blocks, but when we read up on the
planning permission we realised it was a way of getting round planning
permission for them as our car parking space is on top of it (there were
protected trees in the way of the space that was on the original plans).
I know it sounds eccentric that we park on top of it... that part of our
garden is a storey below street level.

We've had constant damp patches ever since we moved in. The parking
space is on a slope and we seem to get all the rain seeping into side of
the outhouse that is at the lowest point. Everything in there is has
mould on it and there is constant condensation inside the glass door. I
have an electrician here today installing a fan, he has noticed there are
two layers of the breeze blocks in the wall with a gap in between and he
can see the bricks are damp in between the gap.

Next to our car parking space there is a narrow gutter leading to a
drainpipe, that is also very narrow, but I can also see dark patches of
damp and mould all over the ceiling of the outhouse (which is wooden
struts supporting plywood and then whatever the builders put above that.

We did manage to get the developer to put some leading around the edge of
the car parking paving, but it hasn't had any affect on the damp as far
as I can see. Our neighbour shares the other half of this outhouse (he
parks his car next to us) and he says there is no point in pursuing the
developer, we just have to work out our own fixes.

If anyone has some advice I would be really grateful, I'm worried the
outhouse will collapse under the weight of our cars as much as anything!


Sounds like it hasnt been €˜tanked - sealed to stop ground water
penetrating. Sometimes this is done on the soil side, sometimes it is on
the inside.

The property should be covered by a 10 year NHBC warranty. Contact them if
the developer wont help.

On 21/01/2020 22:17, Brian Reay wrote:

Sounds like it hasnt been €˜tanked - sealed to stop ground water
penetrating. Sometimes this is done on the soil side, sometimes it is on
the inside.

And/or no damp proof course

And/or damp proof course bridged.

And/or car parking roof hasn't got a slope and/or is leaking especially
if the roof is flexing due to varying loads (with and without the car).

If the electrician fitting the fan has noticed wet bricks/blocks high up
the wall then the water is probably getting in from the top.


The property should be covered by a 10 year NHBC warranty. Contact them if
the developer wont help.

+1
Share the cost with the neighbour and get a real surveyor to inspect and
give a report giving indicative cost to repair. Don't rely on a report
by the developer or a third party.
Based on this report get the developer a chance to correct the faults
and invoke the NHBC warranty.

I would be very wary about parking a car on structure that is so wet
where some, or all, of the support is wood.


--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On Tuesday, January 21, 2020 at 7:20:14 PM UTC, wrote:
On Tuesday, 21 January 2020 15:03:15 UTC, Anna Bonaddio wrote:

I would be very grateful for some advice on this. We bought a house from a developer two years ago, the house included what we thought was a useful outhouse that could become a mancave at some point... simple construction, built with breeze blocks, but when we read up on the planning permission we realised it was a way of getting round planning permission for them as our car parking space is on top of it (there were protected trees in the way of the space that was on the original plans). I know it sounds eccentric that we park on top of it... that part of our garden is a storey below street level.

We've had constant damp patches ever since we moved in. The parking space is on a slope and we seem to get all the rain seeping into side of the outhouse that is at the lowest point. Everything in there is has mould on it and there is constant condensation inside the glass door. I have an electrician here today installing a fan, he has noticed there are two layers of the breeze blocks in the wall with a gap in between and he can see the bricks are damp in between the gap.

Next to our car parking space there is a narrow gutter leading to a drainpipe, that is also very narrow, but I can also see dark patches of damp and mould all over the ceiling of the outhouse (which is wooden struts supporting plywood and then whatever the builders put above that.

We did manage to get the developer to put some leading around the edge of the car parking paving, but it hasn't had any affect on the damp as far as I can see. Our neighbour shares the other half of this outhouse (he parks his car next to us) and he says there is no point in pursuing the developer, we just have to work out our own fixes.

If anyone has some advice I would be really grateful, I'm worried the outhouse will collapse under the weight of our cars as much as anything!

I can't help thinking there's just not enough info here. As a short term measure I'd plug a dehumidifier in. A fan I would not expect to keep on top of it or prevent further damage, and the damage from mould can be extensive and very expensive.

I'd suggest posting some pics of the outside so we can see what the relationship is between the outhouse & ground levels, slopes, water drainage etc.. Maybe some pics showing construction details on the outhouse too. I'll admit to being surprised that, IIUC, you're parking your car on a plywood roof. Details might help, that might be a problem area in a couple of ways.


NT

here are some pics

Anna Bonaddio wrote:

here are some pics

You'll have to upload photos somewhere (own website, google photos,
flikr, imgbb, etc) then paste links to them ...

On Thursday, January 23, 2020 at 3:22:58 PM UTC, Anna Bonaddio wrote:
On Tuesday, January 21, 2020 at 7:20:14 PM UTC, wrote:
On Tuesday, 21 January 2020 15:03:15 UTC, Anna Bonaddio wrote:

I would be very grateful for some advice on this. We bought a house from a developer two years ago, the house included what we thought was a useful outhouse that could become a mancave at some point... simple construction, built with breeze blocks, but when we read up on the planning permission we realised it was a way of getting round planning permission for them as our car parking space is on top of it (there were protected trees in the way of the space that was on the original plans). I know it sounds eccentric that we park on top of it... that part of our garden is a storey below street level.

We've had constant damp patches ever since we moved in. The parking space is on a slope and we seem to get all the rain seeping into side of the outhouse that is at the lowest point. Everything in there is has mould on it and there is constant condensation inside the glass door. I have an electrician here today installing a fan, he has noticed there are two layers of the breeze blocks in the wall with a gap in between and he can see the bricks are damp in between the gap.

Next to our car parking space there is a narrow gutter leading to a drainpipe, that is also very narrow, but I can also see dark patches of damp and mould all over the ceiling of the outhouse (which is wooden struts supporting plywood and then whatever the builders put above that.

We did manage to get the developer to put some leading around the edge of the car parking paving, but it hasn't had any affect on the damp as far as I can see. Our neighbour shares the other half of this outhouse (he parks his car next to us) and he says there is no point in pursuing the developer, we just have to work out our own fixes.

If anyone has some advice I would be really grateful, I'm worried the outhouse will collapse under the weight of our cars as much as anything!

I can't help thinking there's just not enough info here. As a short term measure I'd plug a dehumidifier in. A fan I would not expect to keep on top of it or prevent further damage, and the damage from mould can be extensive and very expensive.

I'd suggest posting some pics of the outside so we can see what the relationship is between the outhouse & ground levels, slopes, water drainage etc. Maybe some pics showing construction details on the outhouse too. I'll admit to being surprised that, IIUC, you're parking your car on a plywood roof. Details might help, that might be a problem area in a couple of ways.


NT

here are some pics - sorry worked out how to do it now!

https://www.flickr.com/photos/186594924@N02/

On Tuesday, January 21, 2020 at 9:45:47 PM UTC, Brian Gaff (Sofa 2) wrote:
What do the local council building control say about what they did, if its
unsafe I'd have thought they could force them to redo all of these stupid
designs, but you may have to lose your car parking spot at least for a time.
Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
wrote in message
...
On Tuesday, 21 January 2020 15:03:15 UTC, Anna Bonaddio wrote:

I would be very grateful for some advice on this. We bought a house from
a developer two years ago, the house included what we thought was a useful
outhouse that could become a mancave at some point... simple construction,
built with breeze blocks, but when we read up on the planning permission
we realised it was a way of getting round planning permission for them as
our car parking space is on top of it (there were protected trees in the
way of the space that was on the original plans). I know it sounds
eccentric that we park on top of it... that part of our garden is a storey
below street level.

We've had constant damp patches ever since we moved in. The parking space
is on a slope and we seem to get all the rain seeping into side of the
outhouse that is at the lowest point. Everything in there is has mould on
it and there is constant condensation inside the glass door. I have an
electrician here today installing a fan, he has noticed there are two
layers of the breeze blocks in the wall with a gap in between and he can
see the bricks are damp in between the gap.

Next to our car parking space there is a narrow gutter leading to a
drainpipe, that is also very narrow, but I can also see dark patches of
damp and mould all over the ceiling of the outhouse (which is wooden
struts supporting plywood and then whatever the builders put above that.

We did manage to get the developer to put some leading around the edge of
the car parking paving, but it hasn't had any affect on the damp as far as
I can see. Our neighbour shares the other half of this outhouse (he parks
his car next to us) and he says there is no point in pursuing the
developer, we just have to work out our own fixes.

If anyone has some advice I would be really grateful, I'm worried the
outhouse will collapse under the weight of our cars as much as anything!

I can't help thinking there's just not enough info here. As a short term
measure I'd plug a dehumidifier in. A fan I would not expect to keep on top
of it or prevent further damage, and the damage from mould can be extensive
and very expensive.

I'd suggest posting some pics of the outside so we can see what the
relationship is between the outhouse & ground levels, slopes, water drainage
etc. Maybe some pics showing construction details on the outhouse too. I'll
admit to being surprised that, IIUC, you're parking your car on a plywood
roof. Details might help, that might be a problem area in a couple of ways.


NT

Thanks very much for this suggestion - I have emailed my local council's buildings control!

On Tuesday, January 21, 2020 at 10:00:45 PM UTC, newshound wrote:
On 21/01/2020 19:20, wrote:
On Tuesday, 21 January 2020 15:03:15 UTC, Anna Bonaddio wrote:

I would be very grateful for some advice on this. We bought a house from a developer two years ago, the house included what we thought was a useful outhouse that could become a mancave at some point... simple construction, built with breeze blocks, but when we read up on the planning permission we realised it was a way of getting round planning permission for them as our car parking space is on top of it (there were protected trees in the way of the space that was on the original plans). I know it sounds eccentric that we park on top of it... that part of our garden is a storey below street level.

We've had constant damp patches ever since we moved in. The parking space is on a slope and we seem to get all the rain seeping into side of the outhouse that is at the lowest point. Everything in there is has mould on it and there is constant condensation inside the glass door. I have an electrician here today installing a fan, he has noticed there are two layers of the breeze blocks in the wall with a gap in between and he can see the bricks are damp in between the gap.

Next to our car parking space there is a narrow gutter leading to a drainpipe, that is also very narrow, but I can also see dark patches of damp and mould all over the ceiling of the outhouse (which is wooden struts supporting plywood and then whatever the builders put above that.

We did manage to get the developer to put some leading around the edge of the car parking paving, but it hasn't had any affect on the damp as far as I can see. Our neighbour shares the other half of this outhouse (he parks his car next to us) and he says there is no point in pursuing the developer, we just have to work out our own fixes.

If anyone has some advice I would be really grateful, I'm worried the outhouse will collapse under the weight of our cars as much as anything!

I can't help thinking there's just not enough info here. As a short term measure I'd plug a dehumidifier in. A fan I would not expect to keep on top of it or prevent further damage, and the damage from mould can be extensive and very expensive.

I'd suggest posting some pics of the outside so we can see what the relationship is between the outhouse & ground levels, slopes, water drainage etc. Maybe some pics showing construction details on the outhouse too. I'll admit to being surprised that, IIUC, you're parking your car on a plywood roof. Details might help, that might be a problem area in a couple of ways.


NT

+1.

Surely not on a plywood roof. That would be evident from inside. At the
least I would expect reinforced concrete beams, or perhaps a reinforced
concrete slab ideally supported on RSJs.

The roof is paving blocks above, and definitely wooden beams underneath. I've posted pictures below.

In my opinion that arrangement looks decidedly dodgy, I would have thought the timber joists would at least sit on the block work rather than a timber beam screwed to the walls and very near to the top course where there will be little support. I would also have a look at that drainage channel it might be a source of damp getting inside. It will be interesting to see what the local BCO says?

Richard

On 23/01/2020 15:35, Anna Bonaddio wrote:


here are some pics - sorry worked out how to do it now!

https://www.flickr.com/photos/186594924@N02/



That brick paving is not waterproof. Water will run through the gaps
between each of the bricks. The gap has probably just been filled with sand.

The metal water drainage gully to the front of the second photo will
only deal with surface water and not any water that has gone down the
gaps between the brick paving.

This means that the layer beneath the brick paving is the bit that needs
to be totally waterproof AND with a means of directing any water that
gets through the bricks to a drain. On the road side the tarmac
pavement is higher than the bottom of your brick paving so the water
cannot escape that way. I see no gutter or downpipe for water in any of
your other photos. I would expected that roof to slope slightly so the
water drains to one end and for there to be an opening to a downpipe to
drain the water away from the roof.

My guess is that the developer hasn't installed a sufficient waterproof
layer under the brick paving, or has installed a layer that is not
robust enough for the intended traffic (the weight of a couple of parked
cars) and the layer has failed and/or the roof doesn't slope
sufficiently for the water to drain to a common point. Every time it
rains you could have a large pool of water under your brick paving that
is probably seeping through any cracks in any waterproof layer and
making the plywood outhouse roof and block walls wet.

If the wooden beams and plywood are the only support for the roof then
now being wet is likly to make the problem worse every time you or you
neighbour parks a car and the wet ply and wood flexes.

Put a spirit level on your brick paving. Is it level or is there a slope?

I doubt if it is condensation.

When the developer later installed the lead flashing was this flush with
the top of the brick paving, was it fitted below the the brick paving or
was it fitted beneath the waterproof layer? If the two former cases it
could have made the problem worse.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On Thursday, 23 January 2020 16:03:52 UTC, Anna Bonaddio wrote:
tabbypurr wrote in message
...
On Tuesday, 21 January 2020 15:03:15 UTC, Anna Bonaddio wrote:

I would be very grateful for some advice on this. We bought a house from
a developer two years ago, the house included what we thought was a useful
outhouse that could become a mancave at some point... simple construction,
built with breeze blocks, but when we read up on the planning permission
we realised it was a way of getting round planning permission for them as
our car parking space is on top of it (there were protected trees in the
way of the space that was on the original plans). I know it sounds
eccentric that we park on top of it... that part of our garden is a storey
below street level.

We've had constant damp patches ever since we moved in. The parking space
is on a slope and we seem to get all the rain seeping into side of the
outhouse that is at the lowest point. Everything in there is has mould on
it and there is constant condensation inside the glass door. I have an
electrician here today installing a fan, he has noticed there are two
layers of the breeze blocks in the wall with a gap in between and he can
see the bricks are damp in between the gap.

Next to our car parking space there is a narrow gutter leading to a
drainpipe, that is also very narrow, but I can also see dark patches of
damp and mould all over the ceiling of the outhouse (which is wooden
struts supporting plywood and then whatever the builders put above that.

We did manage to get the developer to put some leading around the edge of
the car parking paving, but it hasn't had any affect on the damp as far as
I can see. Our neighbour shares the other half of this outhouse (he parks
his car next to us) and he says there is no point in pursuing the
developer, we just have to work out our own fixes.

If anyone has some advice I would be really grateful, I'm worried the
outhouse will collapse under the weight of our cars as much as anything!

I can't help thinking there's just not enough info here. As a short term
measure I'd plug a dehumidifier in. A fan I would not expect to keep on top
of it or prevent further damage, and the damage from mould can be extensive
and very expensive.

I'd suggest posting some pics of the outside so we can see what the
relationship is between the outhouse & ground levels, slopes, water drainage
etc. Maybe some pics showing construction details on the outhouse too. I'll
admit to being surprised that, IIUC, you're parking your car on a plywood
roof. Details might help, that might be a problem area in a couple of ways.


NT

Thanks very much for this suggestion - I have emailed my local council's buildings control!

Well that should ensure you some extra grief.

As for your plywood & block roof, that looks suspect to me. No way would I park on it. I'd want a reinforced concrete roof as a minimum to park on. It's perfectly possible that's what you have above the ply, but If I were building such a thing I'd have removed the timbers once set, and used junk wood to support it during production. The whole thing looks suspicious.

I can't see in the pics what the pattern of wetness is.


NT

On Thursday, 23 January 2020 23:34:57 UTC, tabby wrote:
On Thursday, 23 January 2020 16:03:52 UTC, Anna Bonaddio wrote:
tabbypurr wrote in message
...
On Tuesday, 21 January 2020 15:03:15 UTC, Anna Bonaddio wrote:

I would be very grateful for some advice on this. We bought a house from

At this point I'd lift a paving block (if it's not firmly attached) to see what's under it. If there is a concrete slab there I'd measure its depth. If you find sand then a sheet of polythene or roofing felt I'd not park on it again.


NT

Anna Bonaddio wrote:

https://www.flickr.com/photos/186594924@N02/

if you measure the external height of the outbuilding, and subtract the
internal height of the plywood ceiling, how much depth is there for
anything structural above it? I'd be amazed if parking two cars on just
a layer of paving blocks didn't show through as dips in the ceiling ...

On 23/01/2020 17:25, alan_m wrote:

My guess is that the developer hasn't installed a sufficient waterproof
layer under the brick paving, or has installed a layer that is not
robust enough for the intended traffic (the weight of a couple of parked
cars) and the layer has failed and/or the roof doesn't slope
sufficiently for the water to drain to a common point. Every time it
rains you could have a large pool of water under your brick paving that
is probably seeping through any cracks in any waterproof layer and
making the plywood outhouse roof and block walls wet.

Off the wall suggestion

https://www.bes.co.uk/testing-equipm...ain/drain-dyes

Get some water trace dye, mix with water and with a watering can soak
your parking space surface, especially the cracks between the bricks.
Perhaps at first just water the bit of the parking space above where the
damp is mostly located. Wait a while and see if you can detect the dye
inside on the ply roof or on the walls. Choose a colour that will show
up against a dark mould.

If you avoid watering the metal gully (shown in the front of the second
photo) you can check other possible drainage points such as the cutter
in the road, the outside of your structure etc.




--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 24/01/2020 09:06, alan_m wrote:
On 23/01/2020 17:25, alan_m wrote:

Off the wall suggestion

https://www.bes.co.uk/testing-equipm...ain/drain-dyes

Alternative suppliers that may have a outlet nearby

Toolstation
https://www.toolstation.com/drain-tracing-dye/p19855

Screwfix
https://www.screwfix.com/p/monument-...rain-dye/31595

Inside it may be easier to trace using a UV torch
Plenty of sellers on Ebay or you may already have something for checking
banknootes
Example (random Ebay listing)
https://tinyurl.com/uohye4k

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mailto : news {at} admac {dot} myzen {dot} co {dot} uk

While the outhouse has a cavity all around 4 walls(?) it is fairly
useless as a vapour barrier if the vapour has nowhere to go other than
to travel through the cement and block into a dryer space.

Others in here with know how may suggest a air-vent arrangement to
better equalise the 2 atmospheres such that the vapour takes the easier
route to the inside room rather than through the wall. The idea being,
to make the air in the cavity circulate as much of the cavity space as
possible.

I notice a lot of wet in the cement lines behind the storage. It's also
a good indicator of how much vapour there is in the cavity/room.

The outside skin of block is covered in a wood panelling. The wood does
not look capable of defending water off. Indeed it may be sourcing water
to the wall. This can help create a 'reservoir' that, itself, has to
evaporate before it will take the water(as vapour) from the outside wall
during the dryer conditions. Further more, it is likely that the panels,
or individual laps of wood are set on rising studs form floor to wall
top suggesting very restricted air flow under the wood and around the
outer wall surface.

You also have plant growth at the far side. Some plants, like creeper,
vine, will drill through cement and cross cavities which can help carry
water to the inner skin. I have seen them wrapped around whole internal
roof structure too. Very invasive plants.

As for the wood structure; a Mini is circa .5 ton. If these beams run
across the path of the car it seems that braking and accelerating in &
out of this space would have a tendency to 'roll' the beams as it
appears they are simply stood on edge independent of one another. They
don't look fixed at all other than to the ceiling. But there will
probably be enough bonding of the materials above

As for sagging. Elevate yourself so to get an eye-line view along the
bottom edge along the length of the wood. Choose a beam which you guess
is where the wheels of the Mini are. You may notice a difference when
the car is on the roof and when it is not. But, without doubt, there
will be sag of some amount.

I don't see where 'water', as in 'a stream of water', is getting in
directly. All I see is vapour problems.

As I said, it appears the wettest part of the room is where the storage
prevents venting or air circulation. Being in a sunken area may mean air
isn't moving around like you would want it to.


....Ray

On 26/01/2020 18:54, RayL12 wrote:

While the outhouse has a cavity all around 4 walls(?) it is fairly
useless as a vapour barrier if the vapour has nowhere to go other than
to travel through the cement and block into a dryer space.

Is it a cavity or just cement blocks with two internal holes?

https://tinyurl.com/vr9tcmc

If its blocks with two holes through the middle there is little
(nothing?) you can do to get air to circulate in the cavity, plus the
there is a direct bridge between the two sides. My guess the wall is
single block wide with wood cladding, perhaps with a waterproof membrane
beneath the cladding.



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mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 26/01/2020 20:18, alan_m wrote:
On 26/01/2020 18:54, RayL12 wrote:

While the outhouse has a cavity all around 4 walls(?) it is fairly
useless as a vapour barrier if the vapour has nowhere to go other than
to travel through the cement and block into a dryer space.

Is it a cavity or just cement blocks with two internal holes?

https://tinyurl.com/vr9tcmc

If its blocks with two holes through the middle there is little
(nothing?) you can do to get air to circulate in the cavity, plus the
there is a direct bridge between the two sides. My guess the wall is
single block wide with wood cladding, perhaps with a waterproof membrane
beneath the cladding.




And totally inadequate for parking a car in top too !.

The side-to-side slope is very obvious from the outside and inside
photos, so even if that plywood decking was actually used as
shuttering to support a poured concrete deck, laying a poured
concrete slab with a slope like that would be difficult, if not
impossible. Those beams would never have supported the weight of
a wet poured concrete deck on their own (one that is strong enough
to support the weight of two cars). They are only suitable for
internal domestic flooring.

You need to find out what is between that plywood deck and the
paving blocks that you park your car on.

Something substantial like a Range Rover could go through that,
hopefully while no-one is in the space below.

Did you get a proper survey done before buying the property ?.
If so, what did it say ?.

On Monday, 27 January 2020 11:15:38 UTC, Andrew wrote:
On 26/01/2020 20:18, alan_m wrote:
On 26/01/2020 18:54, RayL12 wrote:

While the outhouse has a cavity all around 4 walls(?) it is fairly
useless as a vapour barrier if the vapour has nowhere to go other than
to travel through the cement and block into a dryer space.

Is it a cavity or just cement blocks with two internal holes?

https://tinyurl.com/vr9tcmc

If its blocks with two holes through the middle there is little
(nothing?) you can do to get air to circulate in the cavity, plus the
there is a direct bridge between the two sides. My guess the wall is
single block wide with wood cladding, perhaps with a waterproof membrane
beneath the cladding.




And totally inadequate for parking a car in top too !.

The side-to-side slope is very obvious from the outside and inside
photos, so even if that plywood decking was actually used as
shuttering to support a poured concrete deck, laying a poured
concrete slab with a slope like that would be difficult, if not
impossible. Those beams would never have supported the weight of
a wet poured concrete deck on their own (one that is strong enough
to support the weight of two cars). They are only suitable for
internal domestic flooring.

You need to find out what is between that plywood deck and the
paving blocks that you park your car on.

Something substantial like a Range Rover could go through that,
hopefully while no-one is in the space below.

Did you get a proper survey done before buying the property ?.
If so, what did it say ?.

Good point about the slope. A closer look at the exterior photo that shows the slope also shows the amount of felt foldover, and I don't believe there's any space there for a concrete slab. It looks like it can only be joists, plywood, felt and paviours. I'd regard parking on there as dangerous until proven otherwise.


NT

On 27/01/2020 11:56, wrote:

Good point about the slope. A closer look at the exterior photo that shows the slope also shows the amount of felt foldover,

That's not felt but the lead flashing that the OP said had been fitted
later (?)

I too missed the slope in the photo. The OP would get most of the water.
If the neighbour has similar problems with damp on on the underside of
the roof on his side of the structure it suggests the roof underneath
the brick paving is leaking

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On Monday, 27 January 2020 13:14:25 UTC, alan_m wrote:
On 27/01/2020 11:56, tabbypurr wrote:

Good point about the slope. A closer look at the exterior photo that shows the slope also shows the amount of felt foldover,

That's not felt but the lead flashing that the OP said had been fitted
later (?)

OK. I'm going to assume they didn't fix boarding to the concrete slab, if it exists, since it would be unnecessary and difficult. But the wood cladding extends too close ot the top for there to be any space for a concrete slab. There's really only room there for plywood, felt & paviours. Also the difficulty of pouring a sloped slab - it's not impossible but I don't remember ever seeing it done, as it's difficult.


I too missed the slope in the photo. The OP would get most of the water.
If the neighbour has similar problems with damp on on the underside of
the roof on his side of the structure it suggests the roof underneath
the brick paving is leaking

which is bound to occur given the load on it. OK for parking bicycles on I guess, not cars.


NT