ProPERLA thermal coating — for walls that need to breathe and brick worth keeping visible

No — and the distinction matters when you are choosing between them. External wall insulation bonds ninety millimetres or more of rigid insulation board to the wall and then renders over it. That gives you a much bigger U-value improvement (typically 60–70%) but it changes the building line by close to a hundred millimetres, needs planning consent in conservation areas, often requires window-reveal re-detailing, and runs to £14,000–£20,000 on a 3-bed semi. ProPERLA is a thin coating applied directly to the existing wall or render. The thermal improvement is smaller (around 29%), but it costs roughly a third as much, takes a week instead of three, does not change the building line by even a millimetre, and is far easier to get through planning on listed or character properties. We quote both side-by-side on the survey where both are options — the right answer depends on your home, your fabric, your budget and your planning context, not on which we would rather sell.

Transparent ProPERLA is a clear version of the coating developed specifically for properties where the original face of the wall must be preserved — listed buildings, conservation areas, Article-4 streets, Georgian and Victorian face-brick terraces, exposed-stone cottages. The chemistry is the same as the pigmented version: water beads off, vapour can still escape, the wall stops drinking the rain. The visual difference is zero — the brick or stone looks exactly as it did before, mortar joints unchanged, weathering pattern unchanged, character intact. It is almost always the version conservation officers will accept on a property where painting is off the table. We have secured approval on Georgian terraces, period rectories, and listed cottages where any pigmented coating would have been refused outright.

On a tired tile or slate roof that is still mechanically sound, ProPERLA Roof is the alternative to a £14,000 re-roof. The process is the same shape as the wall version, with a few specifics. First we soft-wash the roof with a tile-safe biocide to kill the moss, algae and lichen at spore level — never with a pressure washer, which strips the ceramic granules from concrete tiles and voids most manufacturer warranties. We hand-scrape thicker moss mats, replace any cracked or slipped tiles, and let the roof dry fully. Then the ProPERLA Roof coating is sprayed in two to three coats, with the same recoat windows the manufacturer specifies. The end result is a clean, even, refreshed roof tone — chosen from the manufacturer's roof palette — sealed against further moisture penetration for 25 years. Typical 3-bed semi: three to five days, scaffold up once.

The written product guarantee is twenty-five years. Independent durability testing — accelerated weathering tests run by the BBA and corroborated by long-term in-service data from the European market — puts the minimum functional life at around fifteen years in driving-rain exposure zone three (severe). That means the written guarantee is deliberately conservative for most UK sites. The most common cause of premature failure across the trade is bad substrate prep on the original install — algae left to grow back through the coating, render cracks left unsealed, walls coated wet — and that is precisely why our application protocol exists. We measure the wall moisture content with a damp meter before any coat goes on. We do not start the coating until the substrate is properly dry.

Yes. ProPERLA can be overcoated with a breathable masonry paint at any point in its life without affecting the 25-year guarantee. Non-breathable plastic coatings — vinyl masonry paints, certain acrylic systems — would trap moisture against the wall and void the cover, which is why every sign-off comes with a one-page maintenance sheet listing the compatible overcoats. If you change your mind on colour in year ten, you have options.

It depends on the source of the damp, and we are straight about this on the survey. If your damp is driven by water penetration through an exposed elevation — wind-driven rain saturating brick or render and conducting through to the inside face — yes, ProPERLA will stop it. The wall stops absorbing the rain, the moisture content drops, the inside face dries out within a couple of seasons. If the damp is from a different source — rising damp from the ground, a leaking gutter or downpipe, a failed flashing detail, condensation from a poorly ventilated room — ProPERLA will not fix it, and we will not sell it to you as a fix. We tell you on the survey what the source is, and if remediation is needed first we either price the remedial work alongside the coating or refer you back to whoever should handle it.

Sometimes. ProPERLA is recognised as a named external coating measure under PAS 2035 and can be included in an ECO4 package on eligible solid-wall homes, typically as part of a fabric-first retrofit alongside loft or cavity insulation. Eligibility depends on EPC band (D–G), council-tax band on the LA Flex extension, and household composition. We check both routes on the same survey visit. The 0% VAT energy-saving materials rules also apply automatically on the install where the property qualifies, which removes another 20% from the headline number. Not every ProPERLA job is grant-funded — a private retrofit on a 1990s semi in a band-D council-tax property typically pays self-funded — and we will tell you which case applies on the survey rather than building false expectation into the quote.

No. The work happens entirely from the outside — scaffold up the day before, application takes three to five days on a 3-bed semi, scaffold down on the final day. You stay in the house throughout. We work around the weather (no application below 5°C, no application on wet substrate) and tell you the day-by-day forecast plan in writing before we start. Dust sheets cover landscaping. Vacuum up behind us. Photos go onto a shared album you keep.

Because it is a different product doing a different job. External wall insulation is ninety-plus millimetres of rigid foam board, mechanical fixings, base-coat, mesh, top-coat render — material cost alone runs to a thousand pounds per face on a typical semi. ProPERLA is two to three coats of a high-performance coating applied directly to the existing wall — less material, less labour, no building-line change, no window-reveal rework. You pay roughly a third of the EWI price and you get roughly half the thermal improvement, which is the right trade-off for a lot of properties — especially where planning, building-line, or budget rule EWI out. Where EWI is the better answer we will say so on the survey and quote the EWI instead.