Repair or Replace Felt Flat Roofs?

felt flat roofs

Bitumen roofs have been used for a long period of time because they have a proven track record.

This longer-lasting roofing material has a lower environmental impact with the bitumen used for flat roofing is a by-product of refining crude oil for use as petrol, diesel and gas. It is better for the environment as you will be able to renovate and maintain your roof instead of replacing it.

How Do You Assess the Condition of Felt Flat Roofs?

A visual inspection will provide an indication of its general condition. Internally, tell-tale signs of water ingress or damp inside on ceilings and outside you should check the roof covering for the following –

Age of Thermal Movement – Bitumen felt will lose its elasticity over a number of years due to expansion, contraction and exposure to the elements. While your roof expands and contracts with heat and cold, felt does not as it becomes hard and brittle. Humps can appear on the joints made on the joists where the felt is being forced to rise. This gives the illusion of a dip or hollow in the roof decking itself. When these occur above standing water they won’t cause many issues but may sometimes open up as water freezes and expands over successive winters.
Even when your roof is a number of years old, if the damage is in a particular area it might be possible to repair. Modern felts have a mineral finish whilst older felt roofs will often have loose chippings covering the field areas which protect the roof against UV rays. A patch flat felt roof repair using a paint-on waterproof could provide you with a solution for at least 12 months.

Lifting or Badly Stuck Joints – Dry joints can be caused by poor materials, workmanship or simply through age. Using a small amount of paint on water-proofer will provide a temporary repair for a flat felt roof.

Blisters or Bumps in Asphalt Roof – Blisters and bumps are caused by moisture trapped underneath the roof surface which then expands with the heat and lifts the felt away from the roof. This does not mean your roof is condemned unless they burst and become hollow or sit below lying water. It is possible to apply a layer on top which is known as an overlay which provides a solution to get more time out of your roof.

Leaking Flashings – Leaking flashings often occur where your flat roof joins with a wall. Water blown against the wall will run behind it and into your property. One possible option could be to remove the old mortar and repoint with the correct mix. A different flashing option may also solve the problem, but care is needed to make sure your roof does not get damaged.
The joint where the flashing is ‘chased’ into the wall needs checking, as water can enter and find its way behind the flashing and onto the roof boards below. In particular cases, it is possible to mastic the joint instead of using a sand and cement mortar.

Choosing a Quick Fix or Long-Term Solution

If you inspect your roof and minor repairs are needed, get in touch with us and we can help.

Here at East Midlands Roofing Solutions, we can also offer a complete felt flat roof installation if required.