I have a garage that id like to turn into a heated workshop...its single
brick thick with a tiled roof and no insulation. any products recommended?

Steve

I have a garage that id like to turn into a heated workshop...its single
brick thick with a tiled roof and no insulation. any products
recommended?

First you need to insulate. Don't worry about the single brick walls,
they're fine.

I'd recommend using 50mm of Celotex/Kingspan (not polystyrene!) solid
insulation on the walls. Then line with plywood, screwed to the walls
through the insulation into the brick. This gives something to hang stuff
off (and attach tall shelving/racking units to), and ensures no cold
bridging through studs or battens. Either paint or plasterboard the plywood.
I'd be inclined to plasterboard for fire safety.

The roof should also be insulated. You must ensure that there is sufficient
ventilation above the insulation. You can probably provide this using air
bricks or tile vents. The exact form of insulation will depend on what you
have. However, 100mm of Celotex/Kingspan would do here, lined with
plasterboard. Ensure there is vapour check on either the insulation or
plasterboard and that it is taped.

Now, a quick heat loss calculation (these may not be very accurate, as I'm
guessing u-Values a bit), assuming a single garage gives me:

Air Changes: 450W
Walls: 225W
Ceiling: 70W
Floor 585W
Access door: 155W (single PVC)
Garage door: 650W

As you can see, the floor and garage door are the real culprits here. You
will serious improve matters by loading the garage door with Celotex and
draft proofing it. You may need to adjust balance weights or springs to
allow for the extra weight.

The floor is less easy to solve. If you no longer wish to park the car in
there, then even 25mm of Jablite will drop the heating requirement
massively, although you need to decide what you need above, either lots of
concrete, or a suspended or floating wooden floor.

As for heating, if you aren't intending to heat constantly, then electric
heating should be fine. If the floor and garage door can be brought down to
reasonable values, then you are talking a peak loss of just under 2kW. A
2.5kW electric convector with fan boost, thermostat and timer would be
indicated. Alternatively, if the house central heating circuit passes nearby
and can be conveniently tapped into, then a 2.5kW radiator or fan convector
would be easily enough. If I didn't intend heating all the time, I would be
inclined to put a programmable room stat and zone valve in there. If the
system isn't suitable for subzoning, you can still install them, but they
would operate as a glorified timed TRV. As you are likely to want the timing
to be less than that of the house, this would not be too bad.

Christian.

R P McMurphey wrote:

I have a garage that id like to turn into a heated workshop...its single
brick thick with a tiled roof and no insulation. any products recommended?



Wood, foil backed plasterboards and rockwool for the walls, or celotex
if space but not cash is limited.

build false ceiling and rockwoool it for teh roof.


Steve

On Wed, 4 Feb 2004 09:37:51 -0000, "R P McMurphey"
wrote:

I have a garage that id like to turn into a heated workshop...its single
brick thick with a tiled roof and no insulation. any products recommended?

I've done exactly this with the same kind of building using 50mm
Celotex sheet.

The roof is a fairly standard trussed type of construction.

The first job was to board over most of what in a house would form the
loft so that I had easy access to walk about and get to the sloping
roof.

It's important to have ventilation behind the insulation on the cold
side, so I fitted soffit vents between each rafter section. For the
roof I then cut and fitted Celotex sheets on the surface of each
rafter, attaching with long drywall screws with washers to spread the
pressure. THis is a very lightweight material, but it's good to fix
it firmly. Cutting and fitting the roof pieces was easy, if a bit
time consuming. I then taped the joints of the Celotex using a
metallised tape to seal against draughts.

For the walls, I built studding using pressure treated timber, 75mm x
50mm with short side facing the wall. This was stepped off by about
25mm from the wall and the frames attached to the floor and to the
joists above, not to the wall. Air bricks were put into each wall.
The Celotex sheet was then cut and friction fitted into the spaces in
the studding and taped. The framing was then clad in 18mm WBP ply
which means that I can fit virtually anything to virtually anywhere on
the wall.

I have up-and-over doors and these certainly needed insulation as
well. I created a wooden frame on the insides in fairly light
timber and attached Celotex into that as well. Some draught strips
were added to the doors as well.

I decided not to go to the upheaval of digging up and insulating the
floor. It worked out by calculation not to be the largest loss of
heat anyway. I could have put in a false wooden floor and insulated
that I suppose, but I didn't want the loss of height or the ramp from
the outside.


The result is well worthwhile. Previously the garage was for workshop
purposes too cold to use for the winter months. I would run two 3kW
fan heaters and it hardly made an impression. I calculated that
uninsulated, it would have taken 12-15kW to achieve 18 degrees or so
inside when it's zero outside.

With the insulation, I calculated that 3-4kW would be required, and
this has proved to be the case. For heating, I fitted a heat
exchanger to the central heating system to create a separate circuit
and run the pipework insulated through ducting buried between the
house and the workshop. Conventional panel radiators in the
workshop provide the heating from that and of course it is configured
as a separate heating zone with its own thermostat and timer.

If you are going to embark on a project like this, it is worth doing a
complete materials list and going along to a timber and materials
merchant like Jewsons and asking them to quote for the whole thing. I
did that and got very good pricing.

To give you an idea, Celotex in 50mm costs about £15-18 for a
2440x1220 sheet.







Steve


..andy

To email, substitute .nospam with .gl

On Wed, 4 Feb 2004 10:31:23 -0000, "Christian McArdle"
wrote:

I have a garage that id like to turn into a heated workshop...its single
brick thick with a tiled roof and no insulation. any products
recommended?

First you need to insulate. Don't worry about the single brick walls,
they're fine.

I'd recommend using 50mm of Celotex/Kingspan (not polystyrene!) solid
insulation on the walls. Then line with plywood, screwed to the walls
through the insulation into the brick. This gives something to hang stuff
off (and attach tall shelving/racking units to), and ensures no cold
bridging through studs or battens. Either paint or plasterboard the plywood.
I'd be inclined to plasterboard for fire safety.

This is basically what I did, Christian, although in speaking to both
Celotex and Kingspan technical departments they recommended using
studded framing fixed top and bottom and ventilation behind. This
also makes for easier fixings. I felt that ply was more suitable
than plasterboard again for strength reasons and less likely to get
dinged in a workshop. Regarding fire, the main risks are solvents
and in a woodworking environment not clearing up the debris properly,
so I've taken care of those.



The roof should also be insulated. You must ensure that there is sufficient
ventilation above the insulation. You can probably provide this using air
bricks or tile vents. The exact form of insulation will depend on what you
have. However, 100mm of Celotex/Kingspan would do here, lined with
plasterboard. Ensure there is vapour check on either the insulation or
plasterboard and that it is taped.

I debated the various ways of doing the insulation including putting
some between and some on top of the rafters, all on top etc.
The rafters are only about 75mm or so and I didn't want to have 100mm
of Celotex on top - it cuts into the space too much. Frankly, the
cutting and fitting was lengthy, so in the end I elected for using the
same 50mm as on the walls. Doing the sums there is very little
overall difference to the building. In my roof construction, soffit
vents (round ones fitting into a hole cut with a hole cutter) worked.

I found that by boarding at ceiling level that the overall heat loss
upwards is reduced. It ends up that the space above achieves a
temperature of about 5-7 degrees on average below that of the space
below, so it reduces the loss through the Celotex anyway. Since I
want to use the top space for storage anyway, I don't really want it
at outside temperatures. The arrangement works well.



Now, a quick heat loss calculation (these may not be very accurate, as I'm
guessing u-Values a bit), assuming a single garage gives me:

Air Changes: 450W
Walls: 225W
Ceiling: 70W
Floor 585W
Access door: 155W (single PVC)
Garage door: 650W

As you can see, the floor and garage door are the real culprits here. You
will serious improve matters by loading the garage door with Celotex and
draft proofing it. You may need to adjust balance weights or springs to
allow for the extra weight.

The door is certainly a big culprit. With a fairly light wooden frame
and Celotex, the extra weight did not seem to be a problem. I may go
back and add heavier sound deadening material later, and that would
impact the




The floor is less easy to solve. If you no longer wish to park the car in
there, then even 25mm of Jablite will drop the heating requirement
massively, although you need to decide what you need above, either lots of
concrete, or a suspended or floating wooden floor.

I have a larger garage and as a proportion, the heat loss was not as
bad though the floor although it is now the largest part. I felt
that digging up the floor and redoing with Jablite was not a practical
proposition and I didn't want to raise the height of the floor, a)
because I need the headroom to the ceiling for various equipment and
b) I didn't want a ramp to outside. If the building were taller, it
would have been interesting to have a raised floor to run ducting for
air extraction for woodworking, but that would need 150mm or so and
that's much too much for whatg I have.



As for heating, if you aren't intending to heat constantly, then electric
heating should be fine. If the floor and garage door can be brought down to
reasonable values, then you are talking a peak loss of just under 2kW. A
2.5kW electric convector with fan boost, thermostat and timer would be
indicated. Alternatively, if the house central heating circuit passes nearby
and can be conveniently tapped into, then a 2.5kW radiator or fan convector
would be easily enough. If I didn't intend heating all the time, I would be
inclined to put a programmable room stat and zone valve in there. If the
system isn't suitable for subzoning, you can still install them, but they
would operate as a glorified timed TRV. As you are likely to want the timing
to be less than that of the house, this would not be too bad.

I did the heating as a separate zone from the CH and via a heat
exchanger. This is the cheapest way to heat. I used conventional
radiators because I don't want fan heaters etc. blowing wood dust all
over the place....




Christian.


..andy

To email, substitute .nospam with .gl

This is basically what I did, Christian, although in speaking to both
Celotex and Kingspan technical departments they recommended using
studded framing fixed top and bottom and ventilation behind.

It probably depends what you want to hang off the walls. A few light shelves
and stabilising connections to floor standing shelving/racking should be OK
to plywood screwed regularly to the wall through 50mm of solid insulation
(and supported properly at the bottom for vertical loads). However, I'd be
worried about connecting kitchen wall units or heavy shelving directly.

I felt that ply was more suitable than plasterboard again for strength
reasons and less likely to get dinged in a workshop.

My personal preference is to use both. Plywood, then plasterboard screwed
directly to it. I have a thing about spiders and find plasterboard easier to
keep clear of the little *******s than plywood, which has nooks and crannies
in the surface that attract cobwebs. It is also far more flame proof. It is
still easy to screw stuff to the wall as the thin layer of plasterboard has
plenty of compressive strength when screwed tightly to the plywood, so long
screws go through the plasterboard, screw nicely into the plywood and have
the insulation behind to make screw length not significant. I'm not talking
about attaching with dabs here.

Frankly, the cutting and fitting was lengthy, so in the end I
elected for using the same 50mm as on the walls. Doing the
sums there is very little overall difference to the building.

You're probably right. With 100mm I was calculating only 70W through the
ceiling. 50mm is probably just fine.

Christian.