7 Signs of a Bad Roofing Job

Having work completed on your roof should mean one less worry. However, in some cases, the work that has been done is not up to standard, potentially leaving you with more problems and a cost to put it right. Here are some of the common signs of a bad roofing job.

1. It’s asymmetric in shape or colour, or not uniform

Your roof should be symmetrical in its shape and colour, and unless you know of a specific reason why this may not be the case, then asymmetry could be a sign of a bad roofing job.

In some cases, new roofing materials such as tiles will not perfectly match the old tiles as they have not been weathered yet. However, if they look like a different material altogether, this could be a concern. If the roof is laid correctly, the rows should also be in straight lines and not slanted.

2. Missing drip edges or underlay

This may not be something you notice straight away, but the drip edges and underlay play an important role in protecting your roof and your home from water damage. If they are missing or not positioned properly, this could be a sign of a bad roofing job. 

The underlay should be underneath the shingles and the drip edge is the piece of metal that protrudes over the gutter between the underlay and the shingles or tiles.

3. Leaks or mould

If you start noticing leaks or mould in your home following the completion of a roofing job, then the job could be to blame. Leaks and dampness suggest your roof isn’t completely watertight and moisture is entering the property. 

This could be due to a cracked or damaged roofing material, missing underlay, or just poorly laid tiles. If leaks start following a roofing job, or existing leaks are not rectified by the roofing job, you should get a second opinion on the problem and the work by a professional. 

4. Rusted, sunken or asymmetric nails

Poor use of nails on your roof may not cause any immediate detriment but they will definitely lead to problems over time, and some nailing mistakes are telltale signs of a bad roofing job. The nails used for roofing should be resistant to rust and weathering, so if you notice rust, then the wrong nails have probably been used. 

The head of the nails should also be flat to the surface of the roofing material, not overdriven and sunken beneath the surface. Finally, the nails should be placed uniformly, with a 2.5cm gap separating them from the edges of the material.

5. Old materials have been used (such as flashing)

If your old roofing material has started to deteriorate, such as the flashing warping, then this should be removed and replaced with new materials. Some unprofessional roofers may try and cut corners by simply reshaping the old flashing and refitting it, but even if it looks in good condition, it won’t be long before the problem recurs. 

6. Poor ventilation

Ventilation is vital for your roof’s health and a lack of ventilation after a roof replacement could suggest poor workmanship or careless oversight. Trapped air within your roof can cause condensation which will eventually turn into more serious moisture problems, such as causing the roof deck to swell, compromising the health of your roof.

7. The old roof decking hasn’t been changed and is rotten

If the roof decking is in good condition and deemed fit to support the new roof, then it shouldn’t need replacing when the new roof is installed. If, however, there are indications of rot or weakness in the deck, then it needs to be swapped out before any further work takes place. If you noticed that the roof deck looked in bad shape before the work commenced, then this should be a red flag.
Unfortunately, bad roofing jobs do happen, particularly when untrained workers attempt to do the work themselves and cut corners. If you do notice any of these signs, the best course of action is to contact a well-reviewed professional roofing company to come out and inspect the work themselves.


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