As you will know from my earlier thread "Size of a double garage", I am -
planners permitting - hoping to have a detached double garage built at the
front of my property.

I have established that, provided it has a floor area not exceeding 30 M^2,
and is made of non-combustible material, it will be exempt from building
regs. This is fine from a fees point of view, but also means that it won't
have a BCO making sure that it's built properly!

I would like to be able to use it from time to time as a workshop, without
requiring too much heat input - which means that it requires a reasonable
degree of insulation. I would appreciate your views on this.

WALLS
Should they be of cavity construction, filled with insulation - or single
brick with some exotic material or other fixed to the inside? What is the
effect of the choice on the ability to fix things to (e.g. shelves) or hang
things (e.g. ladders) on the walls?

DOOR
I rather fancy an automated roller door - like the ones made by Henderson et
al - with double skin aluminium which is foam filled. Does anyone have any
experience of these? Are they robust and reliable? What are their thermal
properties?

FLOOR
It will have a concrete floor. It would be nice to have some form of
insulation (rigid foam or whatever) under the concrete - but is this
practical, bearing in mind that it needs to take the weight of two cars?

ROOF
I'm currently undecided about a flat (felted) or pitched (tiled) roof.
What's the best way of insulating it? I'd rather like exposed beams from
which I can hang things - and to make use of the available storage space if
I go for a pitched roof - but still need to get some insulation in
somewhere. Any thoughts?

ELECTRICS
Haven't really thought about them yet, but I shall need some light and
power. I assume that they will have to be Part P compliant, even if the
structure is exempt from building regs?
--
Cheers,
Roger
______
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In article ,
Roger Mills \(aka Set Square\) wrote:
I would like to be able to use it from time to time as a workshop, without
requiring too much heat input - which means that it requires a reasonable
degree of insulation. I would appreciate your views on this.

Light & draught.

As a workshop you might want to have natural light wherever possible - but not
suffer the draughts from an open car-sized door.

--
John Cartmell john@ followed by finnybank.com 0845 006 8822
Qercus magazine FAX +44 (0)8700-519-527 www.finnybank.com
Qercus - the best guide to RISC OS computing

Roger Mills (aka Set Square) wrote:

I would like to be able to use it from time to time as a workshop, without
requiring too much heat input - which means that it requires a reasonable
degree of insulation. I would appreciate your views on this.

WALLS
Should they be of cavity construction, filled with insulation - or single
brick with some exotic material or other fixed to the inside? What is the
effect of the choice on the ability to fix things to (e.g. shelves) or hang
things (e.g. ladders) on the walls?

Well if you went for cavity, then the inner leaf would typically be some
sort of insulating block - ok ish for fixing to but not ideal. If you
went for single skin with a studwork frame stuffed with PIR foam then
you could clad it all in ply which gives you an easy way to fix anything
anywhere. Probably work out more pricey than blockwork though.

FLOOR
It will have a concrete floor. It would be nice to have some form of
insulation (rigid foam or whatever) under the concrete - but is this
practical, bearing in mind that it needs to take the weight of two cars?

I would expect if you laid out a grid of rebar and wired it together
before pouring the screed it would be plenty strong enough. It is not
really carrying the load of the cars - it just needs to spread it a
little before it is transferred to the jablite (or whatever you use). A
quarter of a tonne (each wheel) over say 1m^2 ought not make a
noticeable impact on the insulation.

ROOF
I'm currently undecided about a flat (felted) or pitched (tiled) roof.
What's the best way of insulating it? I'd rather like exposed beams from
which I can hang things - and to make use of the available storage space if
I go for a pitched roof - but still need to get some insulation in
somewhere. Any thoughts?

Flat roof with exposed beams would suggest a warm deck construction -
quick and easy. Nothing to stop you from pitching it a little either to
get better run-off (or use steepish firrings). Tiles and a pitched roof
would probably look nicer though - again you can do a warm deck type of
construction with those IIRC. Have a poke around either the kingspan or
celotex site I have a feeling they had an application note showing a way
of doing this.

ELECTRICS
Haven't really thought about them yet, but I shall need some light and
power. I assume that they will have to be Part P compliant, even if the
structure is exempt from building regs?

You could argue that if building control are not involved you can do
whatever you like ;-)

Some questions that need thinking about first though: Is the building to
be joined to the house or some distance from it? How were you planing on
heating it? What sort of workshop tools do you expect to want to use out
there?

Having come out with a power budget, add enough contingency to it to
make sure you cover any likely future use. If you are going to the
hassle of digging a trench for a SWA you may as well make it a big one
since the cable costs will be negligible in the grand scheme of things.
It is also worth thinking through what happens under fault conditions,
so for example what is the implication of losing the lights should you
trip the power circuit with a power tool etc.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Thu, 2 Mar 2006 22:01:58 -0000, "Roger Mills \(aka Set Square\)"
wrote:

As you will know from my earlier thread "Size of a double garage", I am -
planners permitting - hoping to have a detached double garage built at the
front of my property.

I have established that, provided it has a floor area not exceeding 30 M^2,
and is made of non-combustible material, it will be exempt from building
regs. This is fine from a fees point of view, but also means that it won't
have a BCO making sure that it's built properly!

I would like to be able to use it from time to time as a workshop, without
requiring too much heat input - which means that it requires a reasonable
degree of insulation. I would appreciate your views on this.

WALLS
Should they be of cavity construction, filled with insulation - or single
brick with some exotic material or other fixed to the inside? What is the
effect of the choice on the ability to fix things to (e.g. shelves) or hang
things (e.g. ladders) on the walls?

I think it's perhaps as broad as it is long.

My starting point was a garage with single brick walls and pillars at
the front and periodically along the sides. I installed stud frames
next to the walls except at the pillars using a gap of about 25 mm
behind. I put 50mm Celotex in the frames and taped them with foil
tape. I then applied 18mm ply across the whole lot. Where the
pillars are, there is just a gap behind the ply. This doesn't make
the garage any narrower from the perspective of getting a car in if I
ever wanted to do so since the width is limited by the pillars at the
front. The other advantage of this approach is that I can fit things
to the walls anywhere without having to tit around with plugs.
For anything heavy like my dust extractor, I can screw to the studs.

The double cavity wall approach would achieve virtually the same
thing, I think. You could compare the insulating properties of each,
but I don't think that there's a great deal in it since the insulating
material is the main determining factor.

Fixing things involves plugs each time unless you do something like
I've done in the past. That is to fit Spur shelving rails at
intervals along the wall for most of the height of the wall. You can
then easily put shelves in and move as needed. Near the top of the
wall you can install a French cleat. This is basically a piece of
timber - e.g. about 70x35mm with a sloping edge at the top. It slopes
back towards the wall. You fit similar pieces the other way round to
the backs of cupboards, boards to hang tools on and so on. A spacer
piece of similar depth is attached to the bottom of the cupboard/board
The items can then be moved around as needed.




DOOR
I rather fancy an automated roller door - like the ones made by Henderson et
al - with double skin aluminium which is foam filled. Does anyone have any
experience of these? Are they robust and reliable? What are their thermal
properties?

I've been researching these to do a swap when it's warmer. The ones
by Henderson et al. are much of a muchness and I was not impressed
with the quality. Plus, I don't care much for the roller slatted
look which strikes me as rather industrial looking.

I'm gravitating towards sectional doors at present as being a better
compromise between functionality and aesthetics.

In terms of manufacturers, Hormann seem to have a much better quality
than the others, but the price reflects that.
If I went with that, I would probably attach Celotex to the inside as
I have with the current (up/over) doors.





FLOOR
It will have a concrete floor. It would be nice to have some form of
insulation (rigid foam or whatever) under the concrete - but is this
practical, bearing in mind that it needs to take the weight of two cars?

Can't help you with that one. The floor was already there and I
wasn't about to dig it up. I did do the calculations of heat loss,
and provided that the walls and roof are insulated, it isn't a great
deal - possibly 1kW or so on this size. I never have cold feet when
I'm working out there, although I do have some anti-fatigue mats to
stand on as concrete does get hard after a while. It also helps if
you drop anything.




ROOF
I'm currently undecided about a flat (felted) or pitched (tiled) roof.
What's the best way of insulating it? I'd rather like exposed beams from
which I can hang things - and to make use of the available storage space if
I go for a pitched roof - but still need to get some insulation in
somewhere. Any thoughts?

Yes. I already had a pitched and trussed roof - felted and battened
same as a house. The storage space is very useful. I fitted 50mm
Celotex across the tops of the rafters leaving the depth of them to
provide ventilation. I suppose I could have fitted 25mm between
rafters and 25mm over the top but it wasn't worth it. I used long
drywall screws with large flat washers and screwed through the Celotex
into the rafters. Gaps were taped. It's arranged that the space
behind the Celotex connects with the space behind the wall framing. I
then put in soffit vents between each pair of rafters to ensure
ventilation. The joists were then boarded throughout apart from
between one pair where a wooden loft ladder is fitted for access .
Behind it is a large removable panel in the floor that provides access
to hoist large but not heavy items up and down. I installed an
electric hoist above the hatch for the purpose.

Not insulating the "ceiling" is deliberate. Usually the ladder and
access trap doors are closed which keeps heat below that level rather
than letting too much warm air convect into the roof space. However,
it does mean that there is some warmth and than is sufficient to
prevent metal items from rusting etc.




ELECTRICS
Haven't really thought about them yet, but I shall need some light and
power. I assume that they will have to be Part P compliant, even if the
structure is exempt from building regs?

My only comment here is to allow for plenty. SWA cable is cheap.
Digging trenches is a pain in the botty.

I put in three compartment trunking around the walls and have run
wiring in PVC singles rather than T&E. Circuits are wired as radials
with one circuit per side. I then have individual 16 and 32A
circuits with IEC 60309 outlets for machinery.

Lighting circuits run in conduits to fluorescent fittings with
electronic ballasts in rows and intervals across the ceiling.

Consumer units are cheap so I put in large ones to accommodate all the
circuit breakers.

I felt that I would rather adopt this approach to make later changes
easier.



--

..andy

The message
from John Rumm contains these words:

I would expect if you laid out a grid of rebar and wired it together
before pouring the screed it would be plenty strong enough. It is not
really carrying the load of the cars - it just needs to spread it a
little before it is transferred to the jablite (or whatever you use). A
quarter of a tonne (each wheel) over say 1m^2 ought not make a
noticeable impact on the insulation.

After all, that's only the same as two of me standing close together.

--
Skipweasel
Pay no attention to the man behind the curtain.

John Cartmell wrote:
In article ,
Roger Mills \(aka Set Square\) wrote:
I would like to be able to use it from time to time as a workshop, without
requiring too much heat input - which means that it requires a reasonable
degree of insulation. I would appreciate your views on this.

Light & draught.

As a workshop you might want to have natural light wherever possible - but not
suffer the draughts from an open car-sized door.


Which moves us on to the missing part of the OP's question: what about
the windows?

If the walls, floor and roof have been insulated, and the door
draught-proofed, what would then be a reasonable standard and size of
windows for a combined garage/workshop?

I have the same problem coming up here, and am finding it hard to decide
between:

1. Shelling out for new PVC DG units... but it's only a wooden workshop,
so that option could easily go OTT in terms of cost. Where *is* the
absolute cheapest end of the market in new windows, anyway?

2. Trawling the local DG suppliers for mis-measured units they want to
get rid of. Not much luck there, so far - all the ones available locally
are proportioned for houses, and would look daft in a low, single-storey
workshop.

3. Using new or reclaimed sealed glazing units in wooden frames...
storing up repair/replacement work for later?



--
Ian White

Ian White wrote:


I have the same problem coming up here, and am finding it hard to decide
between:

1. Shelling out for new PVC DG units... but it's only a wooden workshop,
so that option could easily go OTT in terms of cost. Where *is* the
absolute cheapest end of the market in new windows, anyway?

2. Trawling the local DG suppliers for mis-measured units they want to
get rid of. Not much luck there, so far - all the ones available locally
are proportioned for houses, and would look daft in a low, single-storey
workshop.

3. Using new or reclaimed sealed glazing units in wooden frames...
storing up repair/replacement work for later?

Option 4 (which worked for me) visit local reclamation yard and pick up
a complete DG window with frame for 20 quid.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
Ian White wrote:


I have the same problem coming up here, and am finding it hard to
decide between:
1. Shelling out for new PVC DG units... but it's only a wooden
workshop, so that option could easily go OTT in terms of cost. Where
*is* the absolute cheapest end of the market in new windows, anyway?
2. Trawling the local DG suppliers for mis-measured units they want
to get rid of. Not much luck there, so far - all the ones available
locally are proportioned for houses, and would look daft in a low,
single-storey workshop.
3. Using new or reclaimed sealed glazing units in wooden frames...
storing up repair/replacement work for later?

Option 4 (which worked for me) visit local reclamation yard and pick up
a complete DG window with frame for 20 quid.

Sorry, I should have mentioned that one too. The local DG makers are
happy for me to go skip-diving, but out here in the country we're still
decades away from replacing old DG.

Reclamation yards are something they have around cities, aren't they?
Around here, decent building materials aren't left lying around -
they're more likely to vanish before you can even blink. (This whole
house was built from top-quality materials, courtesy of king and
country. When the troops marched out of the army camp in 1946, the
locals marched in and recycled the whole place as a service to the
environment.)


--
Ian White

Ian White wrote:
John Cartmell wrote:
In article ,
Roger Mills \(aka Set Square\) wrote:
I would like to be able to use it from time to time as a workshop, without
requiring too much heat input - which means that it requires a reasonable
degree of insulation. I would appreciate your views on this.

Light & draught.

As a workshop you might want to have natural light wherever possible - but not
suffer the draughts from an open car-sized door.


Which moves us on to the missing part of the OP's question: what about
the windows?

If the walls, floor and roof have been insulated, and the door
draught-proofed, what would then be a reasonable standard and size of
windows for a combined garage/workshop?

I've just had my old DG replaced, and kept all of the sealed units.

I now have the luxury of triple glazing (as I kept the originals and
bolted the new into the recess) in my humble workshop ;-)

Cheers

Paul.

John Rumm wrote:

Flat roof with exposed beams would suggest a warm deck
construction - quick and easy. Nothing to stop you from pitching
it a little either to get better run-off (or use steepish
firrings). Tiles and a pitched roof would probably look nicer
though

And the pitched frame provides excellent storage for all those lengths of
timber, moulding, pipe, ladders, etc.

In an earlier contribution to this discussion,
John Cartmell wrote:

In article ,
Roger Mills \(aka Set Square\) wrote:
I would like to be able to use it from time to time as a workshop,
without requiring too much heat input - which means that it requires
a reasonable degree of insulation. I would appreciate your views on
this.

Light & draught.

As a workshop you might want to have natural light wherever possible
- but not suffer the draughts from an open car-sized door.

Yes, I'm planning on having a decent window on one side - which I previously
omitted to mention. The other side is close to a row of leylandii, and the
back is close to the site boundary, facing a public footpath. I suppose I
could have some skylights?!
--
Cheers,
Roger
______
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spam.

In an earlier contribution to this discussion,
John Rumm wrote:

Ian White wrote:


I have the same problem coming up here, and am finding it hard to
decide between:

1. Shelling out for new PVC DG units... but it's only a wooden
workshop, so that option could easily go OTT in terms of cost. Where
*is* the absolute cheapest end of the market in new windows, anyway?

2. Trawling the local DG suppliers for mis-measured units they want
to get rid of. Not much luck there, so far - all the ones available
locally are proportioned for houses, and would look daft in a low,
single-storey workshop.

3. Using new or reclaimed sealed glazing units in wooden frames...
storing up repair/replacement work for later?

Option 4 (which worked for me) visit local reclamation yard and pick
up a complete DG window with frame for 20 quid.

The builder that I'm likely to use sometimes has second-hand windows which
he has removed from other jobs when doing extensions etc., so that is
another possibility.
--
Cheers,
Roger
______
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spam.

In an earlier contribution to this discussion,
John Rumm wrote:


WALLS

Well if you went for cavity, then the inner leaf would typically be
some sort of insulating block - ok ish for fixing to but not ideal.
If you went for single skin with a studwork frame stuffed with PIR
foam then you could clad it all in ply which gives you an easy way to
fix anything anywhere. Probably work out more pricey than blockwork
though.
How about blockwork, and then clad *that* with plywood?

FLOOR

I would expect if you laid out a grid of rebar and wired it together
before pouring the screed it would be plenty strong enough.

Could I simply use a heavy wire mesh, rather than individual bars? What
depth of screed would be needed to prevent it cracking under point loads?

ROOF
Tiles and a pitched
roof would probably look nicer though - again you can do a warm deck
type of construction with those IIRC. Have a poke around either the
kingspan or celotex site I have a feeling they had an application
note showing a way of doing this.

A pitched roof with insulation immediately under the tiles sound good - so
that the storgae space is on the 'warm' side of the insulation.

ELECTRICS
Haven't really thought about them yet, but I shall need some light
and power. I assume that they will have to be Part P compliant, even
if the structure is exempt from building regs?

You could argue that if building control are not involved you can do
whatever you like ;-)

Not sure that 2-Jags would see it that way!

Some questions that need thinking about first though: Is the building
to be joined to the house or some distance from it? How were you
planing on heating it? What sort of workshop tools do you expect to
want to use out there?

It will be 7 or 8 metres from the house. I'd probably use a couple of fan
heaters on the odd occasions when I was working in cold weather. I'm not
proposing to use any tools which need more than a 13a plug each - drills,
circular saw, hand-held power planer, etc.

The minimum requirement is for lighting, and power for the door. I *could*
run an extension lead from the house for the tools - but it would be much
better to have permanent power in there.
--
Cheers,
Roger
______
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spam.

In an earlier contribution to this discussion,
Andy Hall wrote:


Fixing things involves plugs each time unless you do something like
I've done in the past. That is to fit Spur shelving rails at
intervals along the wall for most of the height of the wall. You can
then easily put shelves in and move as needed.

Not quite sure what you mean. What do they look like?

Near the top of the
wall you can install a French cleat. This is basically a piece of
timber - e.g. about 70x35mm with a sloping edge at the top. It slopes
back towards the wall. You fit similar pieces the other way round to
the backs of cupboards, boards to hang tools on and so on. A spacer
piece of similar depth is attached to the bottom of the cupboard/board
The items can then be moved around as needed.

Now that's a really good idea!

DOOR

I'm gravitating towards sectional doors at present as being a better
compromise between functionality and aesthetics.

I'm not quite sure what is meant by the term 'sectional' in this context.
How do they fold, or whatever, and where do they go to when open?


ROOF

Yes. I already had a pitched and trussed roof - felted and battened
same as a house. The storage space is very useful. I fitted 50mm
Celotex across the tops of the rafters leaving the depth of them to
provide ventilation.

That seems like the way to go. Many thanks.
--
Cheers,
Roger
______
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spam.

In an earlier contribution to this discussion,
Christian McArdle wrote:

WALLS
Should they be of cavity construction, filled with insulation - or
single brick with some exotic material or other fixed to the inside?

The latter. Build a studwork frame inside the brick outer. Fill frame
with Kingspan. Line with 12mm WBP ply. This means you can screw and
mount things really easily. If you feel you might convert the garage
into habitable space in the future, put some additional insulation in
front of the studs as well.

I'm currently undecided about a flat (felted) or pitched (tiled)
roof. What's the best way of insulating it? I'd rather like exposed
beams from which I can hang things - and to make use of the
available storage space if I go for a pitched roof - but still need
to get some insulation in somewhere. Any thoughts?

Kingspan again. Use breathable membrane under the tiles and wedge
Kingspan right up to the surface. Better still, insulate between and
above the rafters.

ELECTRICS
Haven't really thought about them yet, but I shall need some light
and power. I assume that they will have to be Part P compliant, even
if the structure is exempt from building regs?

Yes. Run at least a 32A circuit to the garage.

Christian.

Many thanks for your thoughts.
--
Cheers,
Roger
______
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On Fri, 3 Mar 2006 15:35:21 -0000, "Roger Mills \(aka Set Square\)"
wrote:

In an earlier contribution to this discussion,
Andy Hall wrote:


Fixing things involves plugs each time unless you do something like
I've done in the past. That is to fit Spur shelving rails at
intervals along the wall for most of the height of the wall. You can
then easily put shelves in and move as needed.

Not quite sure what you mean. What do they look like?


They are steel rails with regular slots. There are then U-shaped
brackets to fit them.

e.g. Screwfix 16003 17905 etc.

Different heights of rail and lengths of bracket are available.

This is a clone of the original Spur Steel-Lok product

http://www.spurshelving.com/html/tra...djustable1.htm

That one is readily available, but it's worth shopping around for
price.




Near the top of the
wall you can install a French cleat. This is basically a piece of
timber - e.g. about 70x35mm with a sloping edge at the top. It slopes
back towards the wall. You fit similar pieces the other way round to
the backs of cupboards, boards to hang tools on and so on. A spacer
piece of similar depth is attached to the bottom of the cupboard/board
The items can then be moved around as needed.

Now that's a really good idea!

Google using "french cleat" and you will get some illustrations of
different ways to do this.




DOOR

I'm gravitating towards sectional doors at present as being a better
compromise between functionality and aesthetics.

I'm not quite sure what is meant by the term 'sectional' in this context.
How do they fold, or whatever, and where do they go to when open?

They take virtually an L-shaped path because that's how the rails run.
When open, the door would end up horizontal, immediately under the
ceiling joists rather than at the level of the top of the door as an
up/over door does.

With my present arrangement of up/over doors, I use the space between
the top of the door and the ceiling (about 300mm) as a space to store
timber. When the door is changed, it will go above this rack and
below the ceiling.

Since the sectional doors are following an L-shaped path, it means
that you can put taller things closer to the doors as well.


Here is an illustration

http://www.hormann.co.uk/uk/en/katal..._garage_doors/

http://tinyurl.com/ry2oq

Depending on product, these are in the £4k area.

The other consideration is if you want to go for a single, full width
door. You will find that there is very little around in the entry
level up/over doors (e.g. Henderson, Cardale, ...) that will go to the
full width you intend. That was one of my reasons, apart from build
quality, for looking at Hoermann. It's worth going to a specialist
place and looking at different ones before you decide. Bear in mind
that lead times are often 6-8 weeks.

Another good quality product is Silvelox. This is from an Italian
manufacturer http://www.silvelox.com/ENG/home_eng.htm

There are a lot more customisation options and they are a bit better
than Hoermann, but cost about 50% more.

I did look at roller shutter doors. From a functionality
perspective, they are good in the sense that they roll into a cassette
typically. You can also get them with insulating material on the
back. Normally the slats are steel or aluminium, sometimes plastic
covered. As I mentioned, although the functionality is attractive,
I don't particularly like the appearance and it wouldn't really go
with the house either.




ROOF

Yes. I already had a pitched and trussed roof - felted and battened
same as a house. The storage space is very useful. I fitted 50mm
Celotex across the tops of the rafters leaving the depth of them to
provide ventilation.

That seems like the way to go. Many thanks.

Since you are having to go for planning permission you can do this.

There is a planning exemption for roof heights to apex of 4m, but I
believe that having it a brick built building makes it permanent and
therefore not exempt.

The storage space is definitely worth having. Perhaps it might be an
idea to do a mockup against a photo of the house using a drawing
package and make sure that the larger roof doesn't make it loom....







--

..andy