Ronseal TERRM750 Thompsons Emergency Roof Repair Mastic 750 ml | Thompson's Emergency Roof Repair Mastic | Size: 750ml | Trowel-applied roof repair mastic | Adheres to virtually any roofi

Application was easy, even in the rain, and has filled some large cracks in the roof covering that have appeared during the last 12 months but which had gone unnoticed until the heavy and frequent rain showers that substituted for "summer 2024". Have reapplied where I wasn't convinced that the coverage was adequate, even though the underside of the roof was drying out; this revealed that the mastic "skins" but stays flexible, which bolds well for lasting until I can effect a more permanent repair. TBH, this surpassed my expectations so I am more that pleased with the outcome, thus far.

This Ronseal Roof Repair is like thick tar. You can put it on the roof even in the wet but make sure you wear gloves as it's not easy to get it off your skin. I've been using this stuff for years across various different houses with flat rooves and it's great, I wouldn't be without it as you only discover a leak when it's raining and this roof sealer can solve the problem instantly.

My 2 year old garden shed recently began to leak. I suspected the water was getting in past the felt nails, as they had been hammered in slightly too far, and had left a minute gap around some of the nail heads. I initially tried using black bitumen paint, but this didn't provide a complete cure, as the inside of the shed roof was still wet to the touch. I needed something more substantial, and this stuff seemed like it could offer the solution. So, having got myself a 750ml tin from Amazon, I gave it a go, spreading it on and around the suspect area, covering the nail heads and any overlaps on the felt. It is fairly easy to apply, but it's best to wear gloves, and have white spirt handy to wipe up spills and unintentional smudges on clothes. From reading the instructions on the tin, a thick ( around 3mm ) applications is best. It does look like it is going to do the job, but as I type this there has been no prolonged rain in my area, hence the 4 stars for the overall rating. I remain confident, and would use this stuff again if needed.....

I should have got a bigger can

Excellent product.

Had a couple of people look at the leaking shed roof......they didn't fix it. A thick layer of this and an occasional big blob on nails / nail holes stopped the leak that nobody else had been able to. Excellent product, has been effective even in recent torrential downpours.

Amazingly good at sealing a gap when the roof is wet. You'll need to order a small trowel to apply it with as it will trash whatever you're using as it's insanely sticky (as is needed!) You need to use the trowel to slop it on and then spread to where needed. This is not a tidy and accurate repair compound but it's very effective

Doesn't work as well as similar products I have previously used. Won't be buying again.