How to Fix a Leaky Roof Drain

What You'll Need
Wire brush
A-frame ladder
Sheet metal
Roofing cement
Coarse sandpaper
Replacement parts and fastenings
Tape measure

Discovering a leaking roof drain can be more than an annoyance, because if it is not repaired quickly, it can be the cause of severe property damage. By having the skill required to fix a leaky drain, you will be able to save the time, money and the hassle that can usually comes with having to hire a professional repairer.

Step #1 – Locate Damage

Locate the damage carefully and examine the entire section of roof drain that appears to be leaking because this will ensure that you are aware of the full extent of the problem. From the ground, use a pair of binoculars to check the roof guttering. Once you have a clearer picture of the situation, set up the ladder in the right position. Do not use a basic straight ladder because this can cause injuries, due to imbalance. As well as presenting a serious injury concern, you will most likely cause more damage if you grip the drain to stop yourself from toppling.

Determine what material your guttering is made from and ensure that any replacement parts are made from the same material. Take measurements so that you have the specifications of any replacement parts that might be required.

Step #2 – Repair or Replace?

Once you have identified the relevant leakage point, you will need to determine whether you only need to patch up the existing roof drain, or replace the section that has become damaged. Consider the extent of the damage that has been caused and the size of the split or hole to help you make a decision. It is better to replace a damaged section if it means not having to continually repair it.

Step #3 - Patch Job 

Where a patch job is required, clean away any debris from the repair site with a wire brush and water. Dry it thoroughly and prepare the surface by rubbing it with coarse sandpaper. Spread roofing cement over the hole in the roof drain and the surrounding area before leaving it to dry. If it is a large hole which has caused significant damage, cover the roof cement with a piece of sheet metal as an additional patch.  

Step #4 – Replace Parts

If the leak has caused a significant amount of damage, it is best to replace the entire damaged section of the roof drain. To do this, initially clean the drain with a wire brush. Pull away the damaged piece of the pipe, unscrewing it from the property if necessary. Scrub the mouth of the sections of drain that remain to remove any remnants of old adhesive.

Apply several beads of caulk to one end of the replacement section of the drain before fitting the new piece to the old. Ensure that they are properly fitted in place before tightening any fixtures that further seal the drain. If necessary, replace the screws that fix the drain to the surface of the property.