How to felt a shed roof

Felting a shed roof is the crucial final step when building a shed. It will keep your shed dry and help protect everything inside it. Although it may seem daunting, felting a shed roof is a simple job that can be completed by a competent DIYer. Before laying your roof felt, make sure the roof boards are completely dry and if you're replacing old felt, remove any existing nails and felt first.

Image showing shed felt cut into three pieces with small piece on apexImage showing shed felt cut into three pieces with small piece on apexImage showing shed felt cut into three pieces with small piece on apexImage showing shed felt cut into three pieces with small piece on apex

1. Measure and cut the felt

First, you need to measure and cut your roofing felt. The standard method involves laying two pieces of felt either side of the shed, with a third piece across the apex of the roof to overlap the other two pieces. If your shed is smaller, you may be able to use two pieces. If you do this, make sure the overlap is positioned to allow water to run over the joint.

When cutting your felt, you need to allow for:

  • 50mm of overhang on the eaves, which is the longer part of your shed.
  • 75mm of overhang on the gable end, which is the end of your shed.

Spend some time measuring up your shed, then lay your felt out and cut it using a sharp knife. If you need to use a ladder, make sure it's on a secure, flat surface and follow the specific safety instructions on your ladder. You can also place the felt on the roof and mark it up in place if you find this easier.

image showing 100mm and 300mm spacing of clout nailsimage showing 100mm and 300mm spacing of clout nailsimage showing 100mm and 300mm spacing of clout nailsimage showing 100mm and 300mm spacing of clout nails

2. Fit your felt

Start by fitting the two pieces of felt on either side of your shed. Remember to leave the correct overhang at the sides and ends when doing this. 

Make sure the felt is flat then secure it using clout nails. At the top of the felt, use clout nails at 100mm intervals. At the bottom, you can use clout nails at 300mm intervals (see image).

Next, you can fit your piece of felt across the apex of the roof and secure it using your clout nails. Make sure you add nails anywhere that two pieces of felt overlap.

securing shed gable end using nailssecuring shed gable end using nailssecuring shed gable end using nailssecuring shed gable end using nails

3. Secure at the gable end

With your felt secure, you can now fix it to the gable end. First, cut the felt at the centre point of the gable end using a craft knife and fold it. You can then nail the felt to the gable end at 100mm intervals using your clout nails.

Once you’ve secured the felt, you can cover it with the fascia boards. Fit your fascia boards over the top of the felt using wood nails, then trim off any excess felt for a neat look.

image showing securing roof felt to side of shed with hammer and nailsimage showing securing roof felt to side of shed with hammer and nailsimage showing securing roof felt to side of shed with hammer and nailsimage showing securing roof felt to side of shed with hammer and nails

4. Secure at the eaves

If your shed comes with a fascia board for the side, you can simply repeat the previous step.

If it doesn't, you'll need to wrap the felt underneath the edge of the shed and secure it with clout nails.

That concludes our guide to felting a shed roof. This is a simple job that if done correctly, will help keep your shed in pristine condition for years to come. If you're building a whole new shed, take a look at our guide to building a shed for some extra pointers.