A poorly maintained roof can result in serious damage to the rest of your house, so make it a top priority to spot and fix problems
Ensuring that your roof is windproof and watertight is one of the most important jobs you can do to protect your home from damage. Although any work is best left to an experienced roofer, it’s important to know the warning signs and to spot leaks and weak spots early. Checking your roof regularly, and especially after storms, is vital. If problems are evident, get repairs done promptly before the roof structure or internal ceilings are damaged.
Scaffolding will generally be required for roof work but initial inspections can usually be carried out from ground level using binoculars, or by carefully looking out from rooflights or dormer windows. The roof’s condition may also be reviewed by checking the underside in loft or attic spaces, especially when it’s raining.
Repairing and overhauling
Traditional roofing materials, and the way they are laid, give character to a building and are part of its vernacular history, so retain them wherever possible. Remember that consent may be needed if changes to a roof covering are to be made or bats or birds are present within the structure. Avoid quick fixes such as bitumen coatings, liquid waterproofing or spray-on foams, as they make it difficult to spot problems and may, in fact, trap moisture, hinder repairs and prevent the reuse of roofing materials in the future.
Tiles break, crack, flake or become loose due to age, wind, frost damage, or even due to birds disturbing them. In some cases, the battens onto which the tiles are hooked can become rotten or beetle infested. With peg tiles, the wooden pegs may also decay over time.
Many of the problems with slates are similar to those with tiles, except that slates are held in place with nails, so individual slates or entire roofs may slip due to ‘nail sickness’ resulting from corrosion or rusting. Slates that have been re-fixed with lead clips or wire may indicate problems.
Ridges and hips
These provide valuable protection and are often pointed with mortar, which may fail and need replacing before water penetrates the gaps.
Roof valleys and parapet gutters
Leaves and debris coupled with the growth of grass and plants may lead to damage and blockages that cause water to back up and overflow into the roof structure. Therefore, regular maintenance to clear obstructions is vital.
The weakest points in a roof are where two surfaces or materials join, such as at parapets and around ➤
chimneys. Lead or zinc flashing is often used to create a seal, but these materials can fail or there may be insufficient overlap to cope with the volume of water. Mortar fillets are also often used to protect these junctions and may also need to be replaced.
Covered in lead, copper, zinc, asphalt or bitumen, flat roofs are particularly vulnerable to splits, cracks and holes. Areas where water is pooling on the surface should be noted. Repairs must be made as soon as possible and loose material re-fixed to avoid further damage. Patching may be possible but, in the longer term, replacement will probably be necessary.
The structure of a roof is as vulnerable to damage as its covering. Timbers might suffer beetle attack or rot, and there may be undersized or distorted rafters, as well as past alterations or settlement of the building. All of these things may cause the roof to sag or undulate and, although often adding character, any roof that is out of true should be investigated, where necessary by a structural engineer. If the problems are caused by damp, locate the source of the moisture and deal with the problem not the symptoms.
Good ventilation to the roof space is essential to avoid condensation, so check the gaps at the eaves are clear. Don’t rely on your roofer to make anything other than minor timber repairs. Instead, employ a good carpenter who will cut out damaged timber and carefully joint in new sections, keeping as much of the original as possible.
● Use binoculars to examine the roof.
● Look for any slipped, broken and missing tiles or slates.
● Pay close attention to junctions and ridges.
● Check the ground and gutters for debris.
● Inside the loft space, look for chinks of daylight.
● Inspect the floor of the loft for tile, slate or mortar debris from the roof’s underside.
● Note condensation on roof timbers or roofing felt.
● During heavy rain, look for areas where water is entering the roof space.
● Note sagging or spilt rafters.
● Using a penknife, probe any areas of timber that appear decayed.
Fit for the future
One of the easiest ways to improve the energy efficiency of your home is to insulate the roof space or top up the insulation already there. Usually this is done by laying insulation material on the ceiling between and over the joists. This may be mineral wool or a natural product such as sheep’s wool that comes in rolls or ‘batts’; another option is a loose-fill cellulose fibre insulation produced from recycled paper.
Before insulating, always ensure there are no damp or condensation problems. If you are using the roof space as a habitable room you will need to insulate under the roof covering itself.
Left: Lead or zinc flashing at junctions can fail so check for leaks regularlyRight: Ornate ridge tiles also provide valuable protection. The mortar pointing may need replacing to avoid water penetrating