Lava 20 liquid flat roofing in Kerry, Cork and Limerick
A liquid applied flat roof system that cures fast and bonds to most decks, including over an existing roof in sound condition. Useful where stripping back is not practical.
Also known as liquid roofing, liquid rubber or a liquid applied flat roof coating over existing felt.
Updated September 2026
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Roofs this suits
Overlays on tired flat roofs
Complicated shapes and many outlets
Roofs with plant and pipework
Jobs that need a short weather window
Often the quickest way to close a flat roof that is still structurally sound.
What you get for the money
Can go over an existing sound roof, so no strip out
Cures fast, short weather window
Follows awkward shapes and pipework
Not a fix for a deck that is already soft or rotten.
Lava 20, in numbers
Typical life
20 to 30 years on a sound deck, with a manufacturer guarantee behind it
Cures in
Rainproof in around an hour in normal conditions, which is why it suits an Irish weather window
Goes over
Existing felt, asphalt, concrete, GRP and most metals, provided what is underneath is dry and structurally sound
Will not fix
A soft or rotten deck, or wet insulation. Those come out first or the new roof fails with the old one
Fitted price guide
Roughly EUR 80 to EUR 130 per square metre, and less again where there is no strip-out
Best for
Awkward shapes, many outlets, pipework and plant, and roofs that cannot be left open
Guide figures for the south west. The saving against a full strip and re-cover is usually in the skip and the labour rather than the material.
The overlay that saves you a strip-out
Lava 20 is a liquid system brushed and rolled over the existing roof, with reinforcement bandaged into every upstand, outlet and corner. Because it goes on wet it follows shapes that sheet materials fight: pipe penetrations, plant plinths, tight internal corners, kerbs at three different heights.
The reason it comes up so often here is the weather window. It is rainproof in about an hour, so we can close a roof between two showers on a day when GRP would not cure and a torch-on felt roof would have to stay open. On a commercial roof over a working premises, that on its own decides it.
What it is not is a way to bury a dead roof. We cut into the existing build-up and check the deck and the insulation before quoting, and if the ply is soft or the insulation is holding water we tell you the overlay is off and price the strip instead. Covering a wet roof is the cheapest thing we could sell you and the most expensive thing you could buy.
Lava 20 is also a good way to make a flat roof sound around an old rooflight. If the dome itself has gone, see skylight replacement.
Lava 20, asked and answered
Can Lava 20 go straight over my old felt roof?
If the felt is stuck down, the deck under it is dry and firm, and the insulation is not wet, then yes and that is exactly what it is for. We open a test square first so that is a finding rather than an assumption.
How is it different from fibreglass?
Both cure into a seamless skin. GRP needs a new ply deck and dry weather, and it is rigid. Lava 20 goes over what is already there, cures fast in poor conditions and stays flexible. Different tools for different roofs.
How long before it can take rain?
About an hour in normal conditions, against a day or more for other liquid systems. That is the whole reason it exists.
Does it come with a guarantee?
Yes, a manufacturer-backed guarantee on top of ours, and it is conditional on the deck being sound. That is another reason we open the roof up and look rather than quoting off a photograph.
How much does Lava 20 cost?
Laid over a sound existing roof, Lava 20 is typically around €70 to €110 per m², so a 20 to 30 m² extension roof usually comes to roughly €1,800 to €3,300. Repairs to the deck, trims or outlets add to that. We confirm the price after opening a test square.
We work with what suits the building
Not sure which material suits your roof?
Send us the address and a couple of photos. We will tell you straight what the roof needs, what it costs and how long it takes.