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

Underlay is the membrane beneath the covering and the roof's second line of defence — everything persistent damp off the levels drives past a tile is supposed to run down it and out at the eaves. On a uniform interlocking tile covering 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 late-twentieth-century estate roofs it fails first at the eaves where sunlight reaches it and where it has been sagging under water for years. With low-lying, sheltered conditions 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 uniform interlocking tile covering a perished underlay is almost always diagnosed after a leak rather than before one. Where access is flat, with driveways and room almost everywhere, 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 late-twentieth-century estate roofs 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 the same failures repeat across whole streets, that is worth knowing before money goes into patches.
What Our Roof Felt & Underlay Repairs Service Includes in St. Mellons
- 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 St. Mellons
Roof Felt & Underlay Repairs in St. Mellons — Common Questions
What are common signs that I may need roof felt & underlay repairs in St. Mellons?
Underlay is the membrane beneath the covering and the roof's second line of defence — everything persistent damp off the levels drives past a tile is supposed to run down it and out at the eaves. With low-lying, sheltered conditions 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 uniform interlocking tile covering, 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 late-twentieth-century estate roofs 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 the same failures repeat across whole streets, a roof felt & underlay repairs job on a uniform interlocking tile covering 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 St. Mellons?
Yes — roof felt & underlay repairs is one of twenty-five roof repairs we carry out on these late-twentieth-century estate roofs, and across the surrounding area including Old St Mellons, Rumney, Trowbridge, Pontprennau and Marshfield.
Do you cover St. Mellons and the surrounding area?
Yes — roof felt & underlay repairs throughout St. Mellons and the places around it, including Old St Mellons, Rumney, Trowbridge, Pontprennau and Marshfield.
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 as easy as it gets on this list, 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 the same failures repeat across whole streets, 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 St. Mellons
We carry out roof felt & underlay repairs across St. Mellons and the area around it including Old St Mellons, Rumney, Trowbridge, Pontprennau and Marshfield. 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 the same failures repeat across whole streets, those two are what make a figure accurate rather than provisional.
Tell us what the roof is doing in St. Mellons and we will look at it. Call 07868 857692, message us on WhatsApp or use the form below.
