If you master the art of building a brick wall then you can build a brick garage. You will do it more quickly if you have some- body to help you, particularly when it comes to flooring and roofing.
Garage joined to the Home
The best garage is one joined to the house because a warm dividing wall will keep it aired and a door connected to the house can be fitted to save your going into the open to get the car out. This door must be asbestos-lined as a fire precaution, and you must get full approval from your local council before starting work.
A joined-on garage should really be considered at the planning stage of a new house. Building on to old property presents problems which are best left to a professional builder. For instance, if your house has a hollow floor, the air bricks which allow a current of air to pass underneath are arranged in pairs, each one of a pair being exactly opposite the other and not staggered. When air bricks are on all four sides of a detached house, a joined-on garage with a solid floor would naturally impede the flow of air.
You could lay the floor of the garage below the air bricks and damp-proof course of the house, but there would be only the imprisoned air inside the garage to serve this side. Too much fresh air will make a poor home for your car; and if there is too little the air bricks on that side will cease to function, damp will accumulate and dry rot break out under the floorboards of the adjoining rooms.
Connecting the air bricks to the outside front or back by means of bent pipes is no answer because a bend in the pipe would impede the flow of air. You could run the pipe straight across the garage to the outside wall, but then it would be in the way of getting your car in and out. If you heighten the floor so that it covers the pipes you will bring the concrete over the level of the damp-proof course of the house.
The obvious answer is a vertical damp-proof course, one side joined to the house damp-proof course and the other protruding slightly above the level of the concrete floor. Fixing that could prove a tricky job.
You could, as an alternative, continue the damp-proof course of the house wall right across the garage and through to the outside of the garage wall, the layer being bituminous felt, thick polythene or a rubberized waterproof compositionbrushed over the base concrete. Then more concrete could be added to cover the pipes leading to the air bricks. This would raise the whole structure to at least the thickness of the pipes.
When a garage of any description is set on damp soil it is advisable to have this inter-concrete membrane in any case.
Another way out of the difficulty would be to lay the garage floor below the damp-proof course and install the type of open fire that depends on a supply of air from underneath the floorboards (underfloor draught fires ). Provided the inlet pipe was correctly positioned and the fire used regularly, air would be sucked in from the far side under the floorboards. These far-side air bricks would of course have to be in perfect condition.
A third way might be to disregard air bricks at the sides of the house altogether and fix in a new lot, or additional ones to those already there, at the front, with corresponding ones at the back — as is the case with a terrace house. This would be effective only if the sleeper walls or a part-solid floor — such as that of a kitchen were not in the way. So again you will have a major job.
There is a problem, too, in joining up a new wall to an old. The ideal method is to knock out half-bricks in alternate courses of the house so that the new bricks will tie in. If the garage is set back slightly from the front of the house, the knocking out of every second or third course might be adequate, because the join would not be so conspicuous; but you would be faced with a different colour of brick!
This problem does not arise with a rendered wall, provided the texture of the new rendering is matched up with the old and then masonry paint or emulsion paint is applied over the lot. Owing to shrinkage, a crack will eventually appear at the join; but after a few years this can be routed out, undercut, and filled with a mix of the same strength as the remainder of the rendering.
One important point to remember when fixing a roof to a lean-to garage attached to the house is to arrange flashing to carry rain from house wall to roof, so that it does not run down in between. Rout out the filling from a course of bricks above the roof to a depth of at least 25 mm (1 in), insert a narrow length of zinc sheet, wedge it in position and replace the mortar pointing. Fold the other side of the zinc over the top of the roof.
If there is room at the side of the house, a very effective plan is to build a garage separately, a metre (3 ft) or so away, leaving a narrow tradesman’s passage between. A door faces down this passage, making the house frontage look twice as wide. With such a construction, you can go in for a building considerably larger than is necessary for the size of your car, using the rear part as a workshop; or you can have double doors at the back leading to a wash-down and soak-away.
The garage has a boarded and felted flat roof which is not actually flat but has a 1 to 60 slope to carry rainwater to a gutter at the side. There is a low parapet in front hiding the roof and giving increased height to the structure.
Provided the position is sheltered, plant pots can be stood immediately behind the parapet with climbers trained over the top.
A garage standing entirely on its own (unattached to the house) can be bought prefabricated; but you should check with your town hall about fire precautions. It may have to be erected at a certain distance from the house and lined with asbestos sheeting.
With some semi-detached houses, there will be only a narrow passage of a metre (3 ft) or so to allow for the comings and goings of the milk boy and refuse collectors. If your next-door neighbour has a similar adjoining passage, you may be able to come to some arrangement with him to knock down the dividing fence and use the combined passageways as a drive leading to two garages built at the back. Two garages built at the same time will economize on building materials, and on labour as well, because you and your neighbour can work together.
An arrangement such as this will, of course, have to be tied up legally.