making a cold garage usable in the winter ..

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Now I'm retired I have a lot of DIY projects that require me to spend time in my garage using a range of tools (from power tools down to electronics). The garage is about 20 years old, single skin house brick, concrete floor, dpm in good nick, pitched roof, usual swing up door, detached. I'm not looking to do a full blown conversion (at least I don't think I am?) but from October to April it's just too cold and damp (it's not leaking - I mean it matches the humidity of the air outside as you would expect) in there to make it workable; obviously any form of heating is a waste of time.
So my plan is to put in some insulation to floor, walls and ceilings and then a small heater .. nothing elaborate or even pretty (nobody's going in there except me .. it's a workshop after all). But I sense all sorts of issues with the walls being single skin and the issue of ventilation etc.
Any advice much appreciated
Thanks guys
 
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And the drafts around the up and over door and its insulation. Once you have insulated the inside you are almost forced then to line the inside of the insulation to provide a useable surface. Is the garage perfectly dry? Are the walls painted?
Taking the roof first, is it a trussed roof, loads of pre-made trusses about 2 1/2" X 1" in section and held together with machine pressed in plates? Or is it cut joists, 4" X 2" rafters with a single joist between each end? I guess the easiest way is to line the under side with foil backed plasterboard (screwed on) and pile on it as much glass fibre you can afford. Leave a loft hatch and put in a light and switch for storing "useful" material up there!
The walls are more awkward, first the inner lining must be chosen, plasterboard is cheap but fragile, chipboard is heavy but you can put up brackets anywhere for shelves. This layer must be directly on top of the vapour control layer (VCL - cheap thin plastic sheeting). Then your boarding must be held up away from the brick walls with some sort of wooden frame work which in turn is screwed and plugged to the brick wall, with a gap big enough for your insulation. Celotex or similar foam needs to be cut accurately to fit between your uprights and any gaps sealed with expanding foam. Glass fibre is easier to stuff into the cavity but must be supported with some wires or with time it will sag down into the bottom of the cavity. The strapping used for bales is very useful for this.
If possible I would cut a small groove right up against the wall in the floor. This is to allow any water water that gets in through the walls to run along this groove and exit via weep holes (6mm) drilled through the groove out through the base side or under the wall.
Frank
 
Frank - thanks very much for this useful reply.
the roof is 4x2 joists so pretty substantial.
The walls are never damp inside, except when it is VERY humid outside and inevitably that damp air gets through (as you point out!) through the gaps around the garage door, and everything heavier than wood sweats!
In fact it is a very dry shell ..never any signs of water/moisture ingress through walls or floor or roof.
I understand your advice re ceiling and walls - the VCL .. should that be stuck to the chipboard rear face or just pinned on before mounting the chipboard? or if I go for plasterboard (which would be ok because the wooden frame would be good for fixing shelving etc.) is there a version which has a waterproof membrane to one side to act as a VCL? My worry about this was that once the void is filled with insulation and wooden framing there is no chance of any ventilation to that area - is that going to be ok?
.. presumably air bricks high up in the end walls to vent the loft space?
the floor slopes down very slightly, towards the drive - I can live with that, or would you advise building it up level?
Great idea about the groove in the floor :)
presumably I could insulate the garage door and fit some sort of draft excluder.
many thanks for your help
 
if the door is metal and the rest is well insulated the door will run like a river as the coldest part
is it open out doors or up and over ??
 
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Hi big-all
It's up and over, steel, the usual
I'd like to retain this opening for getting larger project pieces in and out.
I have this idea: devise an inner construction that maintains the insulation quality across the garage door but make it removable (e.g. a pair of fully insulated wooden doors made bespoke) ... and put a side door into the side wall for mainstream use.
Too complicated? maybe I should just ditch the up and over and put a pair of insulated swing doors there (vertical hinge)
thanks
 
CELOTEX .. not used this before .. I see it comes in thicknesses from 12mm to 100mm !!! Any advice on that one please. I know the obvious answer is "as thick as you can afford" but isn't the 100mm intended for use in Antarctica rather than warming UK climates?! Would 50mm be a good compromise?
 
Hi big-all
It's up and over, steel, the usual
I'd like to retain this opening for getting larger project pieces in and out.
I have this idea: devise an inner construction that maintains the insulation quality across the garage door but make it removable (e.g. a pair of fully insulated wooden doors made bespoke) ... and put a side door into the side wall for mainstream use.
Too complicated? maybe I should just ditch the up and over and put a pair of insulated swing doors there (vertical hinge)
thanks
thinking outside the box
at a point just below the pivot point off the door fix a moveable horizontal counter with a protective wooden top this will allow stuff to be taken in and out with half the effort
you could also have a curtain off some description you put in place with the door open to fill the space to the counter to help trap the air whilst you pass things in and out
this off course relies on the operating mechanism being above the pivot point
 
100mm is the standard for a domestic loft. In general its half the thickness of glass fibre for the same insulation value. There are all sorts of foam, PIR,PUR, polystyrene. . . All have fairly similar insulation values (+-10%).
Up and over door, the panel is not such a problem. Its the edges that are problematic especially as the frame of the panel is weedy and flexible. Ideally compression seals are required but the obvious area has all ready been used by the door installers, leading to the drafts.
Frank
 
Ok thanks for all your advice here guys
It's one for the summer so I'll give it all some thought over the next few months and do some planning.
Once again, forum proves its worth
 

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