The flat roofs with which most garages are equipped are commonly prone to a range of issues, including leaks, bowing and rotting. This is especially true in areas subject to a lot of rainfall, as well as when the roof is surrounded by trees overhead.
The vast majority of garages are not adequately maintained but are instead used as storage space. This means that not only are your stored items in danger of being damaged by the water from the leaks but also that the lifespan of the structure is reduced. This problem can be resolved by replacing your existing flat roof with a pitched (apex) roof.
How to add a pitched roof to your garage
Step 1
To help determine the kind of pitch you want on your garage, use the pencil and paper to sketch ideas and try out different orientations and roof types. Ideas to try include the hipped roof with its short ends characterised by sloping planes.
Another idea would be the gable roof which resembles the roofs many people would have drawn when they were asked to draw a roof on a house as a child, with its upside-down ‘V’ shape, triangular face and two planes of equal size.
A butterfly roof (which resembles an inverted gable roof) would be another idea if you would like a quirky shape, but if you have an adjoining garage we would recommend a shed roof, which is distinguished by its one-way slope.
Step 2
Keep the roofing structure, but remove the finish (usually felt) and check for water damage, before replacing any rotten sheathing or joists.
Step 3
Install the rafters: start at the apex of the roof by holding the braced ridge boards in place and cut a notch in the rafter (called a ‘birdsmouth’) where it meets the building plate at an angle. This will allow your roof to accept the wooden top plates and beams.
Step 4
The remaining rafters should then be placed 40cm on centre.
Step 5
Use polythene sheeting and exterior-grade plywood to sheath the roof framing.
Step 6
Examine the structure to ensure that it has been soundly constructed and is properly in place, by checking that it is not sheared by lateral pressure. This can be done simply by pressing on the side of the garage.
If the structure moves/sways, then the garage structure will need to be reinforced at the point at which the stud framing intersects with the joists. This can be done using knee bracing, as well as diagonal bracing across the interior side of the framing/sheathing at the structure’s corners.
Step 7
Apply the roofing felt as underlay, in addition to shingles or rolled roofing and finish by installing flashing at intersecting planes, soffits and fascia to the exposed eaves, windows and doors.
Alternatively, we supply a range of concrete garages that come readily equipped with pitched roofs. For more information, call Dencroft now on 0800 1182547.