A properly installed, quality roof is crucial to maintaining a house's integrity. The roof must do more than just keep wind and rain out of the house. It must also help the house "breathe" by allowing moisture-laden air generated in the house or in the attic space to escape. If it doesn't, when the warm air collides with cold objects in the attic, it results in condensation. Condensation is water, and water dripping inside a house can generate a host of other related problems such as rot and structural weaknesses.
For these reasons, homeowners sooner or later ask themselves, "Do I need a new roof?" or "How much does a new roof cost?" To appraise the quality of your roof, follow this inspection checklist.
Roof Inspection Checklist
1. From outside:
Using a pair of binoculars or standing on a ladder at roof level, look at the overall appearance of your roof. In particular, look for the following indicators of potential roof problems:
- Are there any blistered, curled, or split shingles? A few can be repaired, but if the general appearance of the roof is poor, it may be time to reroof.
- Are there loose or missing shingles or tiles?
- Do you see any exposed nails? They are a source of leaks.
- If your roof is covered with composition (asphalt) shingles, look for dark patches indicating the granular coating has worn away.
- Look for significant accumulation of granules in your rain gutters. Some granules are normal, but a lot, combined with dark patches on your shingles, is a sign of an aging roof.
- Look for sagging along the ridges or in the middle of the roof.
- Check where ridges and hips meet. Shingles may break or work loose in these spots.
- Any rusty metal or displaced shingles along the valley are signs of roof weaknesses.
- Inspect the flashing around plumbing vents and chimneys. Loose shingles or rusty, loose flashing is another sign of trouble. Step flashing around chimneys must be well embedded in the mortar between bricks.
- Where a vertical side of the house meets the roof, such as along dormer walls, flashing should be firmly in place or it is a potential leak.
- Check the gutters closely for sagging and signs of leaks between sections. Are the downspouts firmly in place and directing water away from the house foundation?
- If you have a shake or shingle roof, inspect the flashing around chimneys and vertical walls carefully because acid in the wood can eat away at the flashing over the years. In consistently moist areas, prevent mildew by regularly removing wet leaves that collect in certain parts of the roof.
2. From inside:
- In the attic, look for signs of leaks. Dark stains on the rafters or the underside of the roof decking material generally indicate water trails. Look for water signs around plumbing vent pipes and along chimneys, skylights, and valleys.
- If you find dark spots, see if they are still wet or are old. Push a sharp screwdriver into the wood. If it is soft, it is a sign of rot. If the wood is stained but still dry and firm during your rainy season, it may be an old leak that has been repaired.
- Look up through the roof for any pinpoints of light. If you find one, run a thin length of wire up through it so you can find it on the roof. Do not widen the hole. Shake roofs in particular may show daylight during the summer months, but the wood will swell shut again with the first rains.
- Look for sagging sheathing between rafters. This is one sign of an old roof in need of repair. Sagging or cracked rafters will certainly require repair or replacement as part of a new roof installation.
3. Flat roof:
- Look for any blisters on the roof. If not already broken, blisters eventually will break, which may allow water to enter the roof. If you find any blisters, slit them with a knife and then coat with asphalt roofing patch material commonly known as roofing cement.
- Look for depressions around vent pipes where water can collect and begin leaking through cracks in the surface. Fill them with roofing cement.
- Check all flashing for any separations by the parapet that rings the flat roof.
- Clean drains at the low end of the roof so water can run off without interruption.