Silicate paint for lime render
Updated: 23 October 2026
Freshly floated lime on a cottage gable can look bone-dry after a week of spring sun while the mortar underneath is still soft and uncarbonated. A silicate paint for lime render stays vapour-open only if you wait out the cure and prime bare lime with a potassium-silicate primer, not a bridging sealer. Paint too early, or use a primer meant for old plastic coatings, and you can stall the lime cure. The four tins are in our [silicate paint comparison](/hub/paints-and-varnishes/silicate-paint). Peter F. updated this page on 23 October 2026. Our amazon.co.uk links may earn a commission at no extra cost to you.
Freshly floated lime on a cottage gable can look bone-dry after a week of spring sun while the mortar underneath is still soft and uncarbonated.
Freshly floated lime on a cottage gable can look bone-dry after a week of spring sun while the mortar underneath is still soft and uncarbonated. A silicate paint for lime render stays vapour-open only if you wait out the cure and prime bare lime with a potassium-silicate primer, not a bridging sealer. Paint too early, or use a primer meant for old plastic coatings, and you can stall the lime cure. The four tins are in our silicate paint comparison. Peter F. updated this page on 23 October 2026. Our amazon.co.uk links may earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Listed use | Primer on the listing | Listed coverage | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Earthborn Earthborn Ecopro 5 L white | Exterior | Silicate or bonding | 5–7 m²/L | 8.6 | about £130.00 | View offer |
| Best value |  Earthborn Earthborn Ecopro 10 L white | Title only | n/a | n/a | 8.2 | about £248.75 | View offer |
| Alternative |  Earthborn Earthborn Ecopro 5 L Sandstone | Exterior | Silicate or bonding | 5–7 m²/L | 8.0 | about £145.00 | View offer |
On this page
Why lime render wants an open finish
Traditional lime render keeps solid brick, stone and cob healthy by taking driving rain and letting moisture evaporate outside. A dense film traps vapour at the cold face, which leads to frost damage and peeling sheets. Potassium-silicate masonry paint is the longer-lasting mineral cousin of limewash, because the binder reacts with the substrate rather than forming a skin, if the render is clean, dry, sound and cured.
Earthborn’s 2026 data sheet gives Ecopro Silicate Masonry Paint an sd value of 0.01 m, and Ecopro Silicate Primer 0.002 m. Preservation contractor Truscott argues, as a trade view rather than a lab test, that limewash stays the more sacrificial finish on delicate fabric and that silicate can blister if damp is trapped behind the face. The four Earthborn Ecopro tins on amazon.co.uk are exterior products.
How long to wait, by maker
Earthborn’s 2026 sheet states about one month (four weeks) of drying per 5 mm of render before silicate goes on lime. A 25 mm coat needs at least five months before priming. Painting sooner can stop the lime curing properly.
Keim’s figures are a different clock and are not interchangeable. General notes cite at least 15 days on new render and 30 days for lime. Product blocks state at least 28 days, carbonation to 2.5 mm, moisture to 5 mm at or below 18% by volume, and 5–30°C. Do not paste Keim’s 28-day or 30-day figures onto an Earthborn tin. Ask your lime supplier for this mortar before priming.
Silicate Primer on bare lime
Once bare exterior lime has cured, with moisture under 15% and temperatures above 8°C day and night, start with Earthborn Ecopro Silicate Primer. The 2026 sheet includes bare lime render and excludes engineered brick. An sd value of 0.002 m bonds the primer to the mineral face and keeps the system open.
Earthborn Bonding Primer is the wrong tin on bare lime. Its 2026 sheet excludes highly absorbent untreated mineral surfaces such as fresh lime plaster, and an sd value of 0.35 m is the less open route for sound old paint. A firm plastic coat is a different decision: see silicate paint vs acrylic. Coverage on open lime sits at the low end of 5–7 m²/L. Pack size is in the silicate paint buying guide. Coat order is in how to apply silicate paint.
Old limewash, salts, and listed facades
Potassium-silicate paint cannot bond through chalky coats. Earthborn’s 2026 data sheet requires limewash, distemper and other water-soluble coatings to come off back to a sound mineral face. Primer over powdery limewash binds to the loose wash and can flake.
Fix salts and active damp before you choose a tin from best silicate paint. A cracked hopper that has left white crystals needs the gutter repaired and the wall dried below 15% moisture. Call a professional for live rising damp, possible lead in pre-1960s paint, or high spray work. Historic England notes that like-for-like maintenance often needs no consent, while a first paint or a swap from limewash to a modern mineral coat can need listed-building consent, and Scotland can differ.
Common questions
How long do I wait before painting new lime render with Earthborn silicate?
Earthborn’s 2026 data sheet gives a rule of thumb of about one month (four weeks) of drying for every 5 mm of render thickness. A 25 mm coat of exterior lime render needs at least five months to cure before priming, and poor drying weather can extend it. Ask your lime supplier, because painting sooner can stop the lime curing properly.
Is Keim’s 28-day rule the same instruction as Earthborn’s lime wait?
No. The two makers publish separate rules that are not interchangeable. Keim Paint Shop’s general note cites 30 days for lime render, while product blocks state at least 28 days plus carbonation to 2.5 mm and moisture at or below 18% to a 5 mm depth. Do not apply Keim’s figures to an Earthborn tin.
Which primer goes on bare exterior lime render?
Bare cured exterior lime render takes Earthborn Ecopro Silicate Primer in the Earthborn system. Its 2026 sheet lists lime render as a suitable bare mineral surface with an sd value of 0.002 m, keeping the wall open. The render should be clean, below 15% moisture, and above 8°C day and night before priming.
Can I use Earthborn Bonding Primer on a bare lime wall and still call it open?
No. Bonding Primer on bare lime is the wrong tin if you want the fully open mineral system. Earthborn’s 2026 Bonding Primer sheet excludes highly absorbent untreated mineral surfaces such as fresh lime plaster, and its sd value of 0.35 m is less open than the 0.002 m Silicate Primer.
Do I need to remove old limewash before applying silicate paint?
Yes. Earthborn’s data sheet requires you to remove limewash, distemper and other water-soluble coatings back to a sound mineral surface before Silicate Primer. Silicate paint bonds chemically with bare masonry rather than acting like surface glue, so powdery limewash underneath lets the new finish flake.
Are the Earthborn silicate tins on Amazon suitable for interior lime plaster?
No. The four Earthborn Ecopro tins on amazon.co.uk are exterior masonry products. For interior lime plaster, Earthborn’s FAQ directs you to Earthborn Claypaint instead, while keeping the same rule of thumb of about one month of drying per 5 mm of plaster thickness.
Does a listed lime facade need consent before I switch to silicate paint?
Historic England advises that like-for-like maintenance often needs no consent, whereas a first paint or a swap from a traditional finish to a modern mineral coating can require listed-building consent if it affects character. Rules in Scotland can differ, so check with your local authority before starting.
Related pages
Sources
Public sources from the research digest, last checked on 22 October 2026. Shelf prices and the one star line are the amazon.co.uk figures in the display file, dated 21 October 2026. The price band is this set, not a market average. No listing was lab-tested.
- VOC Regulations 2012 (retrieved 22 October 2026)
- Keim: silicate paints (retrieved 22 October 2026)
- Keim Soldalit (retrieved 22 October 2026)
- Keim application notes (retrieved 22 October 2026)
- Earthborn Silicate Masonry Paint data sheet 2026 (retrieved 22 October 2026)
- Earthborn FAQs (retrieved 22 October 2026)
- Earthborn silicate paint safety data sheet 2022 (retrieved 22 October 2026)
- Historic England: redecorate (retrieved 22 October 2026)