A roof in poor condition lets the elements get at the rest of the building so it’s important to keep it in good condition.
But there again, a roof problem will put a lot of buyers off a property, so it means there’s a chance of a bargain if you can tackle the work.
Highest Safety Levels
The most important thing about working on a roof is to keep safe. There are various ladder attachments that will hook over a roof ridge to hold the ladder in place but properly erected scaffolding is the best way to go.
That way, even if you slip off the roof, the scaffolding should arrest your fall. Don’t try and lean sideways from a ladder either, go back down, move it across and go back up again. Tedious, but safe.
Scope the Work
Trying to decide whether a property needs complete re-roofing or can be repaired is probably a job for an expert.
Anyone can spot loose or broken slates but bumps and sags caused by movement in the supporting timbers may have happened years ago or just last month, and it’s unlikely that a layman will be able to spot the difference.
Main Ridge Roof Components
There are normally three main parts to a pitched roof in the United Kingdom. The supporting structure will usually be made of timbers with rafters between them forming the skeleton of the roof.
Then there is a layer of breathable insulation such as roofing felt or, more recently, a plastic or foil membrane, often with a reflective heat-insulating layer. This is held onto the skeleton with battens.
The final layer is the exterior covering, which in the UK is likely to be slate, clay or concrete tiles or pantiles, although wood and stone have been used in the past.
Moulded tiles such as clay or concrete will have ‘nib’s, which allow one tile to hook over the top of the one underneath it, so they don’t have to be nailed in place.
Slate tiles are completely flat and need to be nailed to the battens though two holes in the top. These nails are often the point of failure in slate roofs and good quality copper or aluminium alloy nails should be used.
Individual tiles that have broken or come loose can be replaced. If they are nailed in place you will need a special tool called a slate ripper, which slides under the tile to break the nail so that the tile can be removed.
You can then fix a replacement tile with a thin strip of lead, zinc or aluminium that can be bent at either end to hook over the tile below and under the replacement tile.
Tiles with nibs can be replaced either by sliding the ones above it up out of the way, or lifting them with wedges (carefully!). Then a new tile can be dropped in and the covering tiles replaced.
Other Roofing Components
While you are up there check on the condition of the ridge tiles, which are at the top of the ridge and should be solidly held down with mortar.
There are also flashings; metal channels that drain water away from the base of the chimney or in valleys between roofs of different pitches. These need to be kept in good condition to stop rain penetrating the fabric of the house.
Flat roofs are often employed for single storey extensions and are constructed from thick wooden joists held parallel by noggins at regular intervals.
Unfortunately flat roofs are notorious for leaking, simply because they are flat; there’s no way to stop the rain sitting on them and eventually it finds a way through.
Some experts believe that you should assume a life of only fifteen years for a flat roof, and then if it lasts any longer it’s a bonus! Newer glues and mastics are coming out now though and some roofing systems offer a twenty-five year guarantee.
Minor problems can be sorted out by cutting away the damaged roof felt and replacing it with a patch, making sure that the area is bone dry before you make the repair and using liquid rubber to bond the two pieces together.
There are also fibreglass-reinforced sheets that can be used to repair larger problem areas.
A Stitch in Time
One of the major points that flat and pitched roofs share is that the earlier you can spot and fix a problem, the better it will be for the property in general.
Rain is the worst natural enemy for houses in the United Kingdom and once damp takes a hold in the structure it can cause numerous expensive knock-on problems.
So whether it’s a complete re-roofing job or a broken tile, it’s best, and cheapest in the long run, to get on with it immediately.