How To Install Roof Felt
Installing a felt roof is an easy and cost effective way to protect a shed, garage, or flat roof. Roof felt is pliable and can be fitted nicely against pitched and curved roofs, it’s applied in layers and covered with a waterproof material which should give you upwards of 20 years protection.
In terms of cost, a small shed should cost in the region of £50 - much cheaper than alternatives such as rubber or fibreglass. A small shed should take just a couple of hours, so even a garage or shed can be done in a day.
This job can be undertaken with no specialist tools, and no naked flames. We recommend you select a professional grade roofing felt no matter the size of the job, it’s far more durable and will withstand weathering - cheaper alternatives can easily become weakened and tear, leaving you repeating the job inside 20 years.
Let’s get started….
- Take a width measurement of your roof, adding 50-75mm to each side to allow for the overhang of the felt. Use a spirit level or straight edge to scratch a marking into your felt. Cut your felt to size along the marking using a Stanley knife.
- Attach your felt with galvanised clout nails - these are shallow enough not to go through the roof. Use temporary nails to hold the felt while you tack it down properly. The nail distances should be roughly 6-7 inches apart. Work slowly and keep things neat. Keep yourself safe by ensuring that if you need to stand on the shed or roof that you support yourself on the strongest load bearing areas.
- If you are working on a shed roof, tack the felt over the edges of the lip of the roof.
- For the corners, use a pig’s ear fold and hold in place with a longer nail. This will leave you with a neat corner.
- If you’re doing a pitched roof, you will want to ‘cap off’ the peak. Use felt adhesive to glue down, and then tack with nails as you did before.
- Trim off any excess polythene and replace the trims.
If you’re laying a flat roof, you will want to do three layers for additional protection; a felt underlay, a second bonded underlay adding gutter drips, and finally a top bonded layer. Finish by felting and edges and flashings. Each layer is bonded using the specialist adhesive and by following the manufacturers instructions with regard to application and timings.
While your felt roof should last upwards of 20yrs, it’s prudent to check annually for rips and tears and maintain accordingly to avoid larger more costly replacements.