Roof Leaks - Causes and Repair

Roof leaks weaken roof structure of the building and destroy household items also. They are irritating and most frustrating to the house owner. More than 90% of roof leaks are caused by improper installation and defective roof flashings.  This article tells about several problems, 

causes and repair of roof leaks.

Roof leaks create several problems as follows. 

• Damages wall plaster and creates dry rot.   
• Leads to increase the growth of molds and bacteria.
• Causes emission of chemical start from building materials.  
• Destroys doors, windows, other timber items and household articles.
• Creates dampness which has adverse effects on the health of inhabitants of the house.
• Roof trusses and ‘Purlins’ starts rotting/rusting from continue exposure to dampness.

How to detect roof leaks?

• Inspect roof regularly and a couple of times during summer and spring seasons.
• Check blockage of rain water pipes and make sure if there is any debris in gutters or on roof. If it is found, clean that immediately.
• Ensure if there is any leakage in the joints of shingles with chimney, vent and skylights.  
• Make sure loose fasteners are tight.

Note down: Repair defective portion of roof immediately. During repairs it is essential to look for any roof deterioration.

Pitched Roof

Pitched roof has more than 10 degrees slope. This roof consists of wooden or iron truss with galvanized sheets, cement sheets, steel sheets or slate shingles and this covering material is fixed on  ‘Purlins’ supported by the truss.

Causes of Leaks in Pitched Roof

• Faulty installation of roof or poor workmanship and inferior quality of materialsused in construction of roof. 
• Improper holes, broken or missing shingles, damaged gutter, vent or chimney surroundings. 
• Heap of waste on roof or in the gutter prevents smooth flow of rain water which causes leakage.             
• Weather effects such as high wind pressure, storm and heavy rain affect roof structure and cause leakage.

How to Repair Leaks in Pitched Roof

Step 1: Make all gutters and roof clean

Clean the gutters for easy and quick flow of rain water. Clear all debris from the roof as it prevents easy flow of rain water and causes damage/ cracking of shingles or sheet due to the weight of debris. Keep rain water pipes clean and check them from time to time to prevent leakage.   

Step 2: Mark actual area of leakage

Know actual causes of leakage and mark leakage area in daylight while it is raining. Take help from professionals in leakage treatment. Actual area of leakage should be calculated with the materials required for repair. The repair of roof leaks should be done before the beginning of rainy season.

Step 3: Tighten loose fasteners and inspect roof regularly

Check the roof after storm and if any fastener or hook is found loose, it should be tightened to avoid any further damage and leakage. Add extra fastener to the roof to avoid further damage to roof if the number of fasteners fixed are less.    

Step 4: Replace missing or broken shingles\sheets

Repair gutters essentially and immediately as they provide direct access to drain off rain water from the roof. Replace missing or broken shingles/sheet at once by properly fixing them with necessary nails or J hooks. Restore defective or missing flashing with the joints of chimney, vent, gutter etc.

Step5: Provide water proof outdoor silicone to prevent leakage

Remove old cracked sealant around the vent or chimney and fill it with proper quality outdoor silicone to prevent any leakage. Fill wrong and defective holes in roof shingles properly with water proof silicone material to avoid leakage through holes. Provide proper quality outdoor silicone to prevent leakage because the sealant around glass of skylight may crack over time and create leaks through the joints.

Step 6: Provide proper overlap

Give proper overlap and if any overlap of shingles or sheet is found improper, change defective, missing or cracked piece of shingle or sheet.

Flat Roof

Flat roof are those roof which have a slope from 1 degree to 5 degrees. This roof is constructed in the same way as a floor and acts as a level platform to support the load. Flat roofs are not considered suitable where rain fall or snowfall is heavy. Flat roof requires weather covering and careful water proofing.

Causes of Leaks in Flat Roof

• Improper slope.
• Obstacles in rain water pipes. 
• Unfinished junction of roof and walls. 
• Damaged water proofing layer.
• Depression on the top of the roof. 
• Defective joints of rain water pipes.  

How to repair leaks in flat roof?

Step 1: Clean roof and check all rain water pipes

Clear all debris from the roof. Check all rain water pipes if there is any blockage in pipes as they provide direct access to rain water and repair defective joints of rain water pipes also. 

Step 2: Mark actual area of leakage in daylight

Know actual causes of leakage and mark leakage in daylight while it is raining. Take help from professionals in leakage treatment. Actual area of leakage should be calculated with the materials required for repair. The repair of roof leaks should be done before the beginning of rainy season.

Step 3: Repair Tar felt water proofing coat and cement concrete ‘gola’

Repair Tar felt water proofing coat if it is damaged and restore damaged cement concrete ‘gola’ in junction of wall and roof slab. 

Step 4: Keep proper slope of tile tracing for smooth flow of rain water

Check the surface of roof and keep the slope of tile terracing in 1:40 ratio to drain off rain water quickly and to avoid leakage. Restore defective joints and repair depressions existing on the top of roof to avoid stagnant rain water which leads to leakage.     

Step 5: Restore the joints of tile tracing

Mend the joints of tile terracing if they are cracked and repair defective/damaged cement pointing to avoid leakage.

Step 6: Check mouths of rain water pipes

Restore the mouth of rain water pipes and repair their cracked joints with tile terracing to avoid leakage.

Step7: Repair leakage in over head water tank

Repair leakage in over head water tank; which destroys water proofing of roof. Fit proper ‘Bal’ cock and over flow pipe in over head water tank to avoid unnecessary over flow of water which damages the roof.

Resource: Gharexpert