Warm Roof Upgrades · Weston-super-Mare & North Somerset
Warm Roof Upgrades In Weston-super-Mare
Is the room under your flat roof freezing, or damp, or somehow both?
Moving the insulation above the deck, where forty years of building science says it belongs
Most flat roofs in Weston built before the 1990s are what the trade calls a cold deck. Insulation sits between the joists, underneath the boards, with a draughty void above it that was supposed to be ventilated and usually is not. It is a design that works beautifully in a textbook and poorly in a real house, because warm damp air from the room below gets into that void, meets a cold deck, and turns back into water. People then spend years hunting for a leak that does not exist. A warm roof turns the whole thing upside down: the insulation goes on top of the deck, under the covering, so the timber stays warm and dry and there is no cold surface inside the build-up for anything to condense onto. It is the single biggest improvement you can make to a flat roof, and the only sensible time to do it is when the covering is coming off anyway.
Free Warm Roof Upgrades Quote
Four boxes and one of us will come and stand on it. Surveys are free, we do not do the three-hour kitchen-table sales pitch, and if your roof has another eight years in it we would rather tell you that than sell you one you do not need.
1,000+
Flat roofs laid, patched or rescued
Houses & Units
Domestic and commercial, same crew
Written Down
Guarantee on paper before we start
Nothing
What it costs to get us on your roof
Why Use Us For Warm Roof Upgrades In Weston-super-Mare?
The condensation problem disappears
No cold surface inside the build-up means nothing for humid indoor air to condense onto. It is not a mitigation or an improvement, it removes the mechanism entirely.
The room becomes usable again
Cold-deck extensions in Weston are notorious for being unbearable in January and a greenhouse in July. Continuous insulation above the deck fixes both ends of that, and heating bills follow.
Your joists stop getting wet
In a warm roof the structural timber sits on the warm side of the insulation. It stays dry, and dry timber does not rot. You are protecting the actual structure, not just the ceiling underneath it.
The falls get sorted at the same time
Tapered insulation is the tidiest way there is to build a slope into a roof that never had one. You are already paying for boards - having them cut to a fall costs less than you would expect.
It brings you up to current standards
Once you are replacing enough of the covering, the insulation requirement applies anyway. Doing it as a warm roof is how you meet it properly rather than fighting to squeeze boards between existing joists.
Done once, while it is open
The cost of doing this alongside a re-cover is a fraction of doing it as its own project later. If your covering is near the end, this is the moment, and we will say so plainly.
"A decent share of the flat roof leaks we are called out to in Weston are not leaks at all. They are condensation inside a cold deck, and the giveaway is a damp patch that is worst in February and clears up by May without anybody touching the roof."
Based on the warm roof upgrades jobs handled by RPS Flat Roofing
How A Warm Roof Upgrades Job Runs
Tell Us What It Is Doing
Where the mark is, when it started, and whether it gets worse in wind or only in long rain. Those two behave differently and it narrows things down before anybody fetches a ladder.
Somebody Stands On It
One of us comes out, gets up there, and walks the whole roof rather than the corner you pointed at. Free, and with no expectation it turns into work.
A Look Underneath As Well
Where there is a ceiling void or a loft hatch, we look at the deck from below too. Half of what matters on a flat roof is invisible from the top.
The Diagnosis, Then The Price
You get told what has failed and why, in words you could repeat to somebody else, before any number is mentioned. Photos where they make it clearer.
A Quote You Can Take Apart
Deck, insulation, membrane, trims and access all listed separately. If you only want part of it done, you can see exactly what that part costs.
Strip Back To Sound Timber
The old covering comes off and the deck gets checked properly. Anything soft comes out. Laying a new membrane over damp boards is how a ten year roof becomes a three year roof.
Falls Before Finish
If the water has nowhere to go, it is going to sit there whatever we cover it with. Firrings or tapered insulation put a proper slope back before the membrane goes anywhere near it.
Water On It Before We Leave
Outlets tested, edges and upstands checked, everything swept up, photographs sent over and the written guarantee handed to you on the day.
What Our Guarantee Actually Covers
Every flat roof in Weston is guaranteed by somebody. Read the small print and you usually find the promise is from the company that made the rubber, not the company that stuck it down. That distinction matters, because membranes almost never fail. Installations do. A sheet of EPDM will happily outlive all of us sitting in a warehouse. It fails at the upstand where somebody rushed the corner.
So RPS Flat Roofing splits the two and tells you both. The materials carry whatever the manufacturer offers, which depends on the product going on your roof - and you are told which product that is, by name, before you agree to anything. Separately, the workmanship carries our own written guarantee, handed over on the day, in language you could read out to a neighbour.
The reason we are relaxed about putting that in writing is that most of the flat roof failures we get called to were decided before the covering went on. Water was never given anywhere to go, or the old deck was left in place because lifting it would have shown up something awkward. Get the falls and the deck right and the covering is the easy part. Get them wrong and no warranty document in the world keeps your ceiling dry.
In Writing
Our Workmanship
Named Product
Maker's Own Cover
Covered
Public Liability
1,000+
Flat Roofs Done
What To Look For In A Warm Roof Upgrades Firm
Ask where the insulation is going
Above the deck is a warm roof. Between the joists is a cold roof. Above the ceiling but below the deck with a ventilated gap is a cold roof pretending. These are genuinely different constructions with different failure modes, and if a quote does not make clear which one you are buying, it has skipped the most important decision in the job.
Ask about the vapour control layer
A warm roof needs a vapour barrier on the warm side, under the insulation, and it needs to be continuous and properly sealed at the perimeter. Miss it or perforate it and you have built a very effective moisture trap. It is invisible when finished, which is exactly why it gets skimped.
Ask what happens to the door and window heads
A warm roof adds real height - often 120mm or more. That has to go somewhere, and around thresholds, door heads and existing upstands it needs thinking about before anybody starts. A firm that has not mentioned this has not measured your roof properly yet.
Warm Deck Against The Cold Deck You Probably Have
| Comparison point | Warm Roof Upgrades | Cold Deck |
|---|---|---|
| Where the insulation sits | Above the deck, under the covering | Between the joists, under the deck |
| Condensation risk | Removed, there is no cold surface | The usual reason these roofs fail |
| Ventilation needed | None, the build-up is sealed | Cross-ventilation, which rarely works |
| Your joists | Warm and dry, on the inside | Cold, and often damp with them |
| Build-up height | Adds 120mm or more on top | No height change at all |
| Meeting Part L | Straightforward to achieve | Hard without losing ceiling height |
The Numbers Building Control Will Actually Ask You About
This is the part most flat roofing sites skip, so here it is plainly. Under Approved Document L, a brand new roof - the one over an extension you are building - has to reach a U-value of 0.15 W/m2K. An existing flat roof that you are renovating or re-covering has to reach 0.18 W/m2K where that is reasonably achievable. And the trigger for all of this is simpler than people expect: replace more than a quarter of the roof's surface and it counts as renovating a thermal element, which means the insulation standard applies whether you had planned on it or not. In practice, hitting 0.18 means somewhere around 120 to 150mm of rigid board depending on the product, which is precisely why it is so hard to do on a cold deck without losing a chunk of your ceiling, and so straightforward on a warm one. For Weston, Worle, Uphill, Hutton, Locking and the North Somerset villages you are dealing with North Somerset Council. Down at Burnham-on-Sea, Highbridge or Cheddar it is Somerset Council, which has been a single unitary authority since April 2023. Get the wrong one and you will lose a fortnight. If your covering is not due for replacement yet, the repairs page covers keeping it going in the meantime.
See what a flat roof costs in WestonWhat Warm Roof Upgrades Costs In Weston-super-Mare
As an addition to a re-cover you are already having done, a warm roof conversion typically adds £45 to £80 per square metre - so on a standard rear extension, somewhere between £900 and £2,000 on top of the covering. Tapered boards to build a fall cost more than flat ones, though usually less than rebuilding a deck to achieve the same thing in timber. Done on its own, as a standalone project with a perfectly good covering coming off, it rarely makes financial sense, and we will tell you that rather than take the work.
See The Full Cost GuideWarm Roof Upgrades - Your Questions
How do I know if I have got a cold deck?
Age is the best clue - almost anything from before the mid-1990s will be one. The symptoms are distinctive too: the room is cold out of proportion to the rest of the house, there is sometimes a musty smell, and any damp patch is worst in the depths of winter and vanishes in spring. A genuine leak does not care what month it is. Condensation cares enormously.
Is it really condensation and not a leak?
Often, yes, and it is the most misdiagnosed thing in flat roofing. The seasonal pattern is the tell. So is damp spread evenly across a ceiling rather than concentrated in one spot, and so is a roof that has already been repaired twice by people who could not find anything wrong with it. If that sounds familiar, you are probably looking at a construction problem rather than a hole.
Will it change how the roof looks from outside?
It gets taller, by 120mm or more. On most extensions and garages nobody ever notices. Where it matters is at door and window heads, at thresholds, and where the roof meets a wall with an existing upstand that now needs to be higher. We work all of that out at survey rather than discovering it on the day.
Can I do it without replacing the covering?
Not really, and that is the honest answer rather than a sales one. The insulation goes underneath the covering, so the covering has to come off. That is why we are so keen for people to think about it at the point the roof is due anyway - the marginal cost then is modest, and doing it as a separate job later means paying twice for the same strip-off.
What about a warm roof on a garage?
If the garage is unheated and stays that way, there is no requirement and often no point. If you are converting it into a room, a gym, an office or anything that will be heated, then the insulation requirement applies and a warm deck is the sensible way to meet it. Plenty of the garage conversions around Worle and Milton fall into exactly this category.
Does a warm roof need ventilating?
No, and that is one of its advantages. A cold deck relies on cross-ventilation through the void to carry moisture away, which needs clear paths and vents that stay unblocked for decades - a lot to ask. A warm roof is a sealed build-up with the vapour control layer doing the work, so there is nothing to block up and nothing to maintain.
While you are here: EPDM Rubber Roofing ·Flat Roof Repairs ·Flat Roof Cost Guide
Where We Work
Warm Roof Upgrades across Weston-super-Mare and out through North Somerset - Worle and Milton, the village cores at Uphill, Hutton and Bleadon, the new streets at Locking Parklands, and down onto the levels towards Highbridge and Burnham.
What People Say Afterwards
Flat roofing is a trade people only think about when something has gone wrong, so the bar is low and the horror stories are plentiful. Here is what customers around Weston and the levels have said about getting it done properly.
Two firms had already patched the same corner of our extension roof and both times it came back by Christmas. Ricky got up there, came down, and said the problem was that the water had nowhere to go - the whole thing sat in a dip. They rebuilt the falls and put rubber over it. Third winter now, still dry, and I have stopped keeping a bucket in the airing cupboard.
Ours is a bungalow near the old village so it is nearly all flat roof, and the salt off the Channel had eaten the edge trims to nothing. Quoted properly, itemised, and the price at the end was the price on the paper. They also spotted that the outlet had been fitted higher than the deck by whoever did it in the eighties, which explained a great deal.
New-ish house, flat canopy section over the front, leaking at one corner. I was braced for being told the whole lot needed replacing. James looked at it and said it was a single lap that had never been properly welded, charged me a fraction of what I had budgeted, and was gone by lunchtime. Genuinely refreshing.
We wanted the garage roof done and were dreading the whole business. Charlie turned up when he said he would, explained the difference between the warm and cold deck options without making us feel thick, and let us take a week to think about it with no chasing phone calls. The crew swept up so thoroughly you could not tell they had been.
We run a unit and the roof had been leaking over the racking for the best part of a year. They worked around us, did the noisy part on a Saturday so we never lost a day's trading, and the report they sent afterwards was detailed enough that our insurer accepted it without a single follow-up question. Cannot ask for much more than that.
I had put off dealing with the dormer for years because every quote I got was for the entire roof. RPS were the only ones who separated out what actually needed doing from what would be nice to do eventually. They did the dormer, told me the main covering had a good few years left, and did not once try to talk me into the bigger job.
Get A Price For Warm Roof Upgrades
Ring and describe what it is doing, or send a message and one of us will come and stand on it. Surveys are free, the number we write down is the number you pay, and if the honest answer is that your roof has another five winters in it, that is what you will be told.