Polar Felt Seal - 500ml, Grey - Waterproof Felt Sealant for Shed Roofs & Garage Roofs - One-Coat Repair - Prevent and Stop Leaks & Cracks - No Primer Needed

The felt roof on our lean-to conservatory was badly worn and caused major leaks indoors. A roofing expert told me the central cracks were too deep to repair, but I went ahead and tried it anyway. I opted for the 2.5-litre tin of Polar Premium, which was easily enough to fill all the deep cracks and then cover the entire surface of the roof. The consistency is thick and tar-like, but remains very easy to apply using any heavy-duty brush. I recommend getting several cheap ones and throwing them away after use as they will be almost impossible to clean. The substance has a relatively strong smell but is not too bad outdoors. It dries quite quickly, creating a rubberised waterproof film. I was delighted this product appears to have remedied all our major leaks after one easy application.

This was the second order for the felt seal in order to complete the sealing on my shed roof. Whilst the quality and finish of the product was good there was a difference in the size of the tins (even though they both stated 500 ml). In addition the sealant in one tin was considerably a darker colour than the other when applied, so even though the job is completed I may have to order yet another tin so that both sides of the shed roof are the same shade. As a result I have deducted a star for the potential cost and extra work to have both sides of the roof looking the same.

It is a 1L tin for minor repairs, those saying it doesn’t go very far, it’s not paint, it’s flat roof repair. I managed to stick down a 10cm wide run of 18ft if that helps judge what you will need. When you first open the tin be very cautious, the liquids separate and need a very good stir, the top will be almost emulsion paint like in texture, the bottom thick tar, it really does need a good solid stir. Wear disposable gloves and old clothes, this stuff isn’t coming off easily if it comes into contact with either. Get an old brush and throw it away afterwards, forget trying to use a roller, it’s also better with a brush as you can work it under and edges. I would definitely use it again if needed, yes it’s expensive but it’s easy to use, it works and it means you can fix the job yourself

Easy to apply and effective. I treated a small felt roof on a garden cupboard but you would probably need two cans to treat a decent-sized garden shed.

Easy to apply, works in well with the tar brush. Seems to cover well and dries in a few hours

Seems to be effective, however a longer period of time required to see its true effectiveness.

Does the job, seals the leaks, however doesn't dry anything like clear

I know it says to mix well before use, but you’ll need a cement mixer to churn this stuff up to be useful. The 1ltr tin I had must have had an inch of settled product at the bottom. Just about got the job done but with this at the bottom of the tin, how effective is the coating going to be?