Hi,

I'm shortly going to be ripping down two crappy old rotten sheds, and
replacing them with a 10' x 13' metal one. The base is patio-type slabs
in concrete; I don't know what's underneath but it's build up 8 or ten
inches above the grass so it's fairly substantial. The surveyor when I
bought the house described it as "sound", while also picking holes in
lots of other things, so I think it's ok. The shed has no floor, and
will fastened directly to the base.

This all seemed fine, but having read some other posts here I'm
wondering if there's likely to be a problem of damp and condensation. It
seems unlikely that the base would include a damp course. I don't need
the shed to feel like my front room, but I do intend to store quite a
lot of stuff down there (I don't have a garage, and the loft hatch is
very small) and I wouldn't want it to be damaged by damp.

Do you think I'm likely to have problems? If so, what can I do about it,
either when building the shed or if I find I have a problem later. I
don't want to spend more than I have to - I wasn't planning to replace
the sheds at all for a while, but I've just discovered quite how rotten
they are and it won't really wait.

Pete

HI Pete

On Thu, 13 Dec 2007 13:43:32 +0000, Pete Verdon
d wrote:

Hi,

I'm shortly going to be ripping down two crappy old rotten sheds, and
replacing them with a 10' x 13' metal one. The base is patio-type slabs
in concrete; I don't know what's underneath but it's build up 8 or ten
inches above the grass so it's fairly substantial. The surveyor when I
bought the house described it as "sound", while also picking holes in
lots of other things, so I think it's ok. The shed has no floor, and
will fastened directly to the base.

This all seemed fine, but having read some other posts here I'm
wondering if there's likely to be a problem of damp and condensation. It
seems unlikely that the base would include a damp course. I don't need
the shed to feel like my front room, but I do intend to store quite a
lot of stuff down there (I don't have a garage, and the loft hatch is
very small) and I wouldn't want it to be damaged by damp.

Do you think I'm likely to have problems? If so, what can I do about it,
either when building the shed or if I find I have a problem later. I
don't want to spend more than I have to - I wasn't planning to replace
the sheds at all for a while, but I've just discovered quite how rotten
they are and it won't really wait.

Pete

If it's one of those Yardmaster sheds then (in my experience or
erecting one of their garages) damp coming up from the floor will be
only a small part of your troubles - the roof on mine leaked like a
sieve !

Metal sheds are prone to condensation problems - and an 'unsealed'
concrete slab floor will cause you problems.

I'd suggest some kind of damp-proof membrane (anything from thick
plastic - slippery to walk on - up to a 'proper' chipboard floor
sitting on timber joists above a membrane).

You'll also want to apply insulation (expanded polystyrene slabs are
probably cheapest) to the inside of the roof, walls and doors - as
otherwise they'll be running wet in no time.

Sorry to be pessimistic - but I wouldn't go the metal shed route
again... ever !

If you insist - do make sure that you have enough self-tapping screws
to finish the job _before_ you start - my Yardmaster kit was short by
about 100 of the little perishers - which meant searching around the
shops for extra screws in little (expensive) plastic blister packs....

My recommendation would be for a timber shed - or even a timber /
steel-frame hybrid like the one I'm currently using for a studio.
Skeleton framework in steel box section, wooden panels screwed to it
with great big self-tapping bolts. Timber roof with two layers of
torched-on felt..... luvverly !

Adrian
West Cork

"Pete Verdon" d wrote in
message ...
Hi,

I'm shortly going to be ripping down two crappy old rotten sheds, and
replacing them with a 10' x 13' metal one. The base is patio-type slabs in
concrete; I don't know what's underneath but it's build up 8 or ten inches
above the grass so it's fairly substantial. The surveyor when I bought the
house described it as "sound", while also picking holes in lots of other
things, so I think it's ok. The shed has no floor, and will fastened
directly to the base.

This all seemed fine, but having read some other posts here I'm wondering
if there's likely to be a problem of damp and condensation. It seems
unlikely that the base would include a damp course. I don't need the shed
to feel like my front room, but I do intend to store quite a lot of stuff
down there (I don't have a garage, and the loft hatch is very small) and I
wouldn't want it to be damaged by damp.

Do you think I'm likely to have problems? If so, what can I do about it,
either when building the shed or if I find I have a problem later. I don't
want to spend more than I have to - I wasn't planning to replace the sheds
at all for a while, but I've just discovered quite how rotten they are and
it won't really wait.


There is only one answer - ventilation. Drill or cut holes top and bottom
both ends and cover with louvred grilles. Circulating air is the only cure
for condensation. I would leave the floor as it's concrete and significantly
above ground level but I would try and allow ventilation of the floor where
possible (use of shelving systems or even duckboards to keep stuff from
lying flat on the concrete).


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

Bob Mannix wrote:
"Pete Verdon" d wrote in
message ...
Hi,

I'm shortly going to be ripping down two crappy old rotten sheds, and
replacing them with a 10' x 13' metal one. The base is patio-type slabs in
concrete; I don't know what's underneath but it's build up 8 or ten inches
above the grass so it's fairly substantial. The surveyor when I bought the
house described it as "sound", while also picking holes in lots of other
things, so I think it's ok. The shed has no floor, and will fastened
directly to the base.

This all seemed fine, but having read some other posts here I'm wondering
if there's likely to be a problem of damp and condensation. It seems
unlikely that the base would include a damp course. I don't need the shed
to feel like my front room, but I do intend to store quite a lot of stuff
down there (I don't have a garage, and the loft hatch is very small) and I
wouldn't want it to be damaged by damp.

Do you think I'm likely to have problems? If so, what can I do about it,
either when building the shed or if I find I have a problem later. I don't
want to spend more than I have to - I wasn't planning to replace the sheds
at all for a while, but I've just discovered quite how rotten they are and
it won't really wait.


There is only one answer - ventilation. Drill or cut holes top and bottom
both ends and cover with louvred grilles. Circulating air is the only cure
for condensation. I would leave the floor as it's concrete and significantly
above ground level but I would try and allow ventilation of the floor where
possible (use of shelving systems or even duckboards to keep stuff from
lying flat on the concrete).



I'd forget ventilation and line it with polystyrene. The key difference
between a shed and a garden studio is insulation. Sounds like the OP
needs something in between.

Stuart Noble wrote:

I'd forget ventilation and line it with polystyrene. The key difference
between a shed and a garden studio is insulation. Sounds like the OP
needs something in between.

Well, it started off as a simple shed just to store stuff in, and been
upgraded in my mind a few times :-) .

I am already planning to line the walls with chipboard or similar to
avoid damaging them when moving stuff around inside (I assume that a
cheap tin shed is going to be pretty thin sheet). The walls are 5'6" or
thereabouts (pitched roof higher in the middle) so I was going to line
it with 8x4 sheets on their sides, leaving 18" at the top where the
wall's less likely to be damaged. Maybe I should be fitting polystyrene
to the walls above that, and to the roof?

I have also seen (and can't remember if I dropped in the "basket" when
buying the shed) solar-powered ventilation cowls, which seem like a
reasonable idea.

I would also aim to keep most things off the floor, on general principles.

Pete

Pete Verdon wrote:
Stuart Noble wrote:

I'd forget ventilation and line it with polystyrene. The key
difference between a shed and a garden studio is insulation. Sounds
like the OP needs something in between.

Well, it started off as a simple shed just to store stuff in, and been
upgraded in my mind a few times :-) .

I am already planning to line the walls with chipboard or similar to
avoid damaging them when moving stuff around inside (I assume that a
cheap tin shed is going to be pretty thin sheet). The walls are 5'6" or
thereabouts (pitched roof higher in the middle) so I was going to line
it with 8x4 sheets on their sides, leaving 18" at the top where the
wall's less likely to be damaged. Maybe I should be fitting polystyrene
to the walls above that, and to the roof?

I have also seen (and can't remember if I dropped in the "basket" when
buying the shed) solar-powered ventilation cowls, which seem like a
reasonable idea.

I would also aim to keep most things off the floor, on general principles.

Pete

I reckon without at least 25mm polystyrene or Celotex on walls and
ceiling it won't be a suitable storage area for anything other than the
lawn mower :-). You could probably just glue it to the metal but it will
damage easily without some sort of covering, and I don't know how easy
that would be to fix. I'd use a moisture resistant flooring grade chipboard

On Fri, 14 Dec 2007 10:36:57 +0000, Pete Verdon wrote:
Stuart Noble wrote:

I have also seen (and can't remember if I dropped in the "basket" when
buying the shed) solar-powered ventilation cowls, which seem like a
reasonable idea.

I put a solar power ventilation fan (not sure if it's the same as your
cowl) in my conservatory roof to try and reduce the heat build up. Even
though you could see the fan spining rapidly when the sun came out, it
failed utterly to make any measurable difference.

--
.................................................. .........................
.. never trust a man who, when left alone ...... Pete Lynch .
.. in a room with a tea cosy ...... Marlow, England .
.. doesn't try it on (Billy Connolly) .....................................