How Much Does It Cost To Replace Roof Felt Under Roof Slates Or Tiles?

Roof felt is a barrier that lies beneath roof tiles in order to prevent weather damage and provide effective insulation. Having intact roof felt is vital to keep water out of your home and to help withstand winds and storms.

However, although roof felt has a long lifespan, it will inevitably deteriorate over time. If you believe that your roof felt requires replacement, you’ll need to know how much it costs to carry out the necessary work.

Roof Felt – What Is It?

Sometimes called roofing underlay, roof felt plays the role of a protecting barrier that keeps your roof watertight. Usually made from a base of cellulose, wood, polyester or fibreglass with an asphalt coating, roof felt guards against exposure to bright sunlight or extreme cold.

Modern roof felt can last for about 30 years and is suitable for use on pitched roofs while also being vital for a flat roof. In most cases, homeowners remain unaware of a problem with their roof felt until they experience a roof leak.

Once this occurs, it’s imperative to seek a repair as quickly as possible to prevent long-standing problems.

What Will It Cost On Average To Replace Roof Felt?

Although it’s possible to only replace a small patch or two of roof felt, it’s often advisable to replace the entire felt to prolong your roof’s lifespan and guard against further property damage.

It will cost from about €200 if only a patch repair is being carried out, but a full professionalroof re-felt starts from around €750 but can be higher depending on your requirements and the size of your roof.

How Does The Re-Felting Process Work?

The process of roof re-felting is as follows:

1. Scaffolding must be erected to allow access to the roof.

2. The existing tiles or slates are removed and then discarded or put carefully away for re-use.

3. The existing felt is removed.

4. Any roof timbers that are rotten are replaced.

5. A breathable membrane will be nailed to the rafters.

6. Battens will be fixed over the membrane.

7. The tiles or slates are refixed to the roof and secured with the battens.

8. New flashing is fitted around roof features and chimney stacks.

Which Factors Affect Roof Felt Replacement Costs?

There are several factors that could impact the cost of your roof felt replacement including:

• Any hidden damage to the roof itself or the underlay that requires additional work.

• Battens – New battens have to be added during a felt replacement which causes the cost to increase.

• Felt – The price of the roof felt will vary depending on the quality and type of material chosen.

• Tiles – it may be advisable to replace all the roof tiles when changing the roof felt.

• Scaffolding – Scaffolding must be erected to complete the job and then dismantled when it is complete.

• Skip hire – When felt and tiles are being replaced, it may be necessary to hire a skip and pay for waste disposal.

• Insulation – If you have cold loft insulation replacement will not be required, but if you’re upgrading to a warm loft insulation option you will need to pay more.