On the Roof
If you don’t see any discolored spots or any other signs leaking inside, it is still a smart choice to have the roof inspected. There could be cracks beginning to form that will become bigger issues down the road. You’ll want to get these problems fixed before they cause any internal damage to the home.
One thing we would recommend is walking the roof to do a simple visual inspection. To be safe, make sure to be aware of where you are on the roof and never walk backwards. Make note of all the penetrations and don’t put any weight on any skylight covers, they’re not built to withstand significant weight. While you’re walking the roof, make a note of how it feels under your feet. If it feels weak, get off the roof safely and as quickly as possible and call a professional roofing contractor.
A leak on the roof could soak the insulation under the membrane. If it feels a spongy underneath you, you’ll also want to refer to a roofing contractor. This is also the case if you notice any water coming out of any part of the membrane.
Inspect Penetrations and their Seals
Next, you will want to look at all the penetrations and seals. A large amount of leaks start at penetrations and seals, which make up a very small percentage of the total area of the flat roof. Penetrations, things like pipes and flashings that ‘penetrate’ the roof, are usually enclosed by flashings made from some form of sheet metal. Inspect around these penetrations for deterioration and cracks. This cracking might not seem to be a big problem, but as moisture gets in, it will expand the crack until its large enough to cause a big leak. Seals are where two waterproof materials overlap, coming together in the same spot. Inspect these seals and make sure they’re smooth and still fully adhering.
In the Interior
You’ll want to check each individual room in the property carefully. Check the ceilings for any stains or discoloration. If the roof is leaking, you’ll find a dark colored ring forming around the water-saturated spot. If you see this, you should contact an experienced roofing contractor before moving ahead with your purchase.
Damage from a leak in one area doesn’t necessarily mean that the leak is located directly above it. Flat roofing systems have layers that might direct the moisture to other areas in the home, many times far away from the source. The damage could also be from a plumbing or AC leak or, possibly some other source other than your roof itself. Its also a possibility that the leak that caused the stain was previously repaired but the discoloration on the ceiling was not. However, to be on the safe side, the best thing to do is to hire a professional flat roofing contractor to locate the source of any leaks.