Roof Repairs › Aberdare › Roof Felt & Underlay Repairs
This page is about roof felt & underlay repairs here specifically — what the fault looks like on these Cynon valley slate terraces, why it happens in this part of South Wales, and what putting it right actually involves.
Call 07868 857692 to arrange an assessment in Aberdare, or message us on WhatsApp.
The Layer Under the Tiles on Aberdare Roofs

Underlay is the membrane beneath the covering and the roof's second line of defence — everything rainfall of that order drives past a tile is supposed to run down it and out at the eaves. On a terrace still on softwood battens the underlay is frequently older bitumen felt, and it is doing more work than anybody realises.
What This Covers
- Damaged underlay
- Torn felt
- Secondary weatherproofing
- Water ingress connected with the affected detail
- Localised weathering or damage requiring repair
Why It Perishes
Bitumen felt goes brittle with age and tears, and on these Cynon valley slate terraces it fails first at the eaves where sunlight reaches it and where it has been sagging under water for years. With rain driven hard against one side there is plenty of water running onto it to find every one of those tears.
You Cannot See It From Outside

Underlay is only visible from inside the roof space or by lifting the covering, so on a terrace still on softwood battens a perished underlay is almost always diagnosed after a leak rather than before one. Where access is stepped so steeply that levels change house to house, an inspection from inside the loft is usually the quickest way to know what you have.
Patching, Eaves Repairs and Re-Covering
A localised tear can be patched or supported by lifting the tiles above it, and on these Cynon valley slate terraces that is a real repair where the rest of the membrane is sound. Where the felt has gone brittle across the whole slope, the only genuine fix is stripping and re-felting as part of a re-cover — and because water finds a defect here within weeks, that is worth knowing before money goes into patches.
What Our Roof Felt & Underlay Repairs Service Includes in Aberdare
- Torn and perished underlay patched beneath lifted coverings
- Eaves felt and support trays renewed at the gutter line
- Breathable membrane fitted where a slope is being stripped
- Underlay inspected from the roof space
- Ventilation checked where condensation is the real problem
- Honest advice where a re-cover is the only lasting answer




Related Roof Repairs in Aberdare
Roof Felt & Underlay Repairs in Aberdare — Common Questions
What are common signs that I may need roof felt & underlay repairs in Aberdare?
Underlay is the membrane beneath the covering and the roof's second line of defence — everything rainfall of that order drives past a tile is supposed to run down it and out at the eaves. With rain driven hard against one side there is plenty of water running onto it to find every one of those tears.
Can a small defect cause an internal leak?
Yes. The kind of defect behind roof felt & underlay repairs lets water into the structure on a terrace still on softwood battens, and it can travel a long way before it shows on a ceiling. That is why the source of a roof felt & underlay repairs problem is traced rather than guessed at from the mark inside.
Will the whole roof need replacing?
Usually not. Roof felt & underlay repairs is repair work, and on these Cynon valley slate terraces the covering around the defect is generally sound — whether a repair is the right answer depends on how far the deterioration has gone beyond the part you can see.
Can you inspect the problem before recommending work?
Yes, always. Given water finds a defect here within weeks, a roof felt & underlay repairs job on a terrace still on softwood battens is looked at before anything is recommended, and you get told what was actually found rather than a figure guessed from the pavement.
Do you cover other roof repairs in Aberdare?
Yes — roof felt & underlay repairs is one of twenty-five roof repairs we carry out on these Cynon valley slate terraces, and across the surrounding area including Aberaman, Cwmbach, Hirwaun, Mountain Ash and Penywaun.
Do you cover Aberdare and the surrounding area?
Yes — roof felt & underlay repairs throughout Aberdare and the places around it, including Aberaman, Cwmbach, Hirwaun, Mountain Ash and Penywaun.
What does a repair like this cost?
Two things set the figure for roof felt & underlay repairs: how far the defect has actually gone, which needs somebody to look at it, and the access. With access here hard to stand a scaffold on, that second one moves the price of roof felt & underlay repairs more than the materials do, and it is why a figure over the phone is a guess.
Can you look at other things while you are there?
Yes, and it is worth it — given water finds a defect here within weeks, safe access to the roof is most of what a visit costs, so anything else wanting attention is far cheaper dealt with on the same day as the roof felt & underlay repairs.
Contact T&T Roofing About Roof Felt & Underlay Repairs in Aberdare
We carry out roof felt & underlay repairs across Aberdare and the area around it including Aberaman, Cwmbach, Hirwaun, Mountain Ash and Penywaun. For roof felt & underlay repairs, a photograph of the affected part of the roof and a short description of what it is doing is the quickest start — given water finds a defect here within weeks, those two are what make a figure accurate rather than provisional.
Tell us what the roof is doing in Aberdare and we will look at it. Call 07868 857692, message us on WhatsApp or use the form below.
