Garage Building

Yes

In theory, water shouldn't be able to penetrate into the cavity, but in principle if it does, it cannot reach the inner skin (even the ties between the two skins should have a drip point formed in them). For better thermal insulation, install cavity insulation 'slabs'.

In theory yes, but probably not......condensation mainly occurs through of lack of ventilation and the atmosphere inside the closed space. IE, If you let damp air in by opening the door, it will also cause condensation.

The inner skin should be in blockwork regardless of the outer skin; the outer skin could be blockwork rather than brick which would increase the thermal properties of the wall, but it would need to be rendered or clad (mainly for aesthetics, but also protection).

However, whatever you use to construct it, most thermal advantages would be lost if you have a bloody great sheet steel up & over door for access......and the number of times you open it.

Consideration should be given to windows and type of roof construction for the same reason.

You could just as easily (if not easier) build it from timber and have little mess; minimal drying out issues; insulate it once the structure is closed in and overall it may be significantly cheaper, while being just as secure (weak point on both a masonry built or timber building will be the door/s)

 

If you aren't concerned about heat, then you really don't need to build a cavity wall..............build it from block and render or clad it.

Cavity wall is only really needed if you are going to heat it or build upwards at a later date.

Admittedly, it would be a bit more secure than a single skin if you can address the access door issues.

 

5 years out.....new technology will be out by then......

 

My workshop is timber studwork, lined on the outside with plywood and clad with weatherboarding.......If someone wants to try to get into it, they are welcome.....once they have got any boarding off, plywood is a b*****d to get through.

The roof is slate, but underneath that is also plywood.

 

In the UK? Don't be daft.......

 

Wood is inflammable and can rot; bricks, breeze, and steel aren't and can't. Just saying.

 

You should also consider cost of materials plus the labour costs......

Blocks don't cost a great deal, really..........until you add on the cost of the bricklayer and his mate etc....

Then add the time it takes to build and the drying time before you can get on with the next stage.

Then on top of that, when the whole build has been finished, there will be quite a while before the masonry and any rendering dries out....50% of which on a single skin construction will be coming out on the inside.

That of course will be at the same time the concrete slab is drying out.

Timber would be quicker to erect and the drying out won't be so much of an issue.

 

Mine won't rot....Tee-hee.

In fact mine will still be standing after the house has fallen down.....

 

Make the slab bigger and the garage bigger - buy more bikes damp proof the slab too...

 

You may already have a slab down but a good builder will not want to risk building on top of it. Footings need to go down at least 12". Also existing concrete floor might only be 3" thick all the way across. Not acceptable. Bear in mind if you was to park a car in the garage where will most of the weight be? A proper concrete floor tends to be a lot thicker on the out side where most of the weight is then when they are approx 2ft in from the walls they will go to around 4" (100mm) thick concrete

 

My slab is roughly 6" thick...........but then, the structure is much lighter in timber (unless you robbed out the oak from the Mary Rose)

 

Condensation occurs when moist air meets a colder surface. Single leaf walls built of masonry are icy cold in winter and for this reason very prone to condensation and claminess even when ventilated. Insulated cavity walls will make a big difference but its an expensive way of reducing condensation in a building used only for storage and not intended to be heated or habitable.
If you are building a garage/workshop which you will spend time in and wish to heat, cavity walls are a big bonus but a cheaper way to a warm(er), dry climate is to build single leaf masonry, cladded on the outside and then add a simple insulated timber skin on the inside. 2X1 battens up the wall with 25mm PIR (celotex) insulation over the top (not between - leave a vent gap) and finished in either plasterboard or plywood will do fine. If you do that though you need to do the ceiling as well or its pointless. The surfaces will to warm to the touch, they will not attract condensation and the air inside the building will remain much drier. Wooden garage doors are far more insulative than sheet metal and will greatly reduce the effect of condensation and cellular composite roller doors running in draught-proofed channels are pretty good as well, but costly. If you're going to those lengths you may as well lay an insulated slab as well. Insulated slabs are perfectly strong if laid correctly. Its all in the preparation.
Building a garage to eliminate surface chill may seem a bit over the top but its well worth thinking about in you're storing expensive motorcycles. They won't sweat or rust and neither will your tools.
My advise to people constructing outbuildings themselves is never skimp below ground because you can't go back and change it. Better to build to a higher spec than you need rather than cut corners to save a few quid, keeping your fingers crossed that what you've done will be enough. A quality, well finished, insulated oversite is there forever. You can always add and improve above ground at a later date as finances allow.

 

Quite true, of course. A wooden building still requires a decent solid, damp-proofed masonry oversite or the structure isn't going to last very long.

 

99% of us would say that wood is flammable.
And if you think Steel isn't I'll pass you some next time I see you that I'll light with a match.