Tuesday, 7 October 2014

Lime Rendering and Limewash

October 4th. It has been difficult to keep this blog updated during the lime plastering. I have generally been leading with pictures and writing a little explanation; but the three coats of lime render and four coats of limewash all look remarkably similar, so I haven't been taking many photos lately.

Lime Render, Coat 1. The mix for this was 1 part lime putty to 2 parts sand. It used about 8 x 18litre pots of lime putty. Greg and I got around 2/3rds of it done in three days, and it was finished off on September 6th - the mass participation event.

Lime Render, Coat 2. I used a 3-to-1 mix with added chopped straw. After a certain amount of experimentation, I found that the easiest way to chop straw was to sprinkle it about and the run the lawn mower over it a few times. This coat was around 10 - 15mm thick. It took 18 to 20 pots of lime putty. We did around half of it on September 6th, and the remainder over the next three days

Lime Render, Coat 3. Same mix as coat 2, but without the straw. I was planning to make this about 5mm thick, but I think it came out thicker - perhaps as much as 10mm. There was a certain amount of hard-trowelling to level, but I finished the surface by hand. About 10 pots of putty, and about 15 person-days work. I finished the rendering with Chris on September 19th, 2 weeks and 2 days after starting.

September 12th - Jane & Harriet working on second coat

Jane and Tessa

Finish coat applied to scratched body coat.

Last section!


I spent the fourth week of September having a big clear-up around the site, and getting on with some long-neglected non-building jobs. This week, September 29 - Oct 3rd, I have applied 4 coats of limewash.

Second coat with raw umber pigment covering white first coat

Same colour! Wet on left, dry on right.

The limewash is essentially the same material as the lime render. You start with lime putty, but add water instead of sand. To apply a coat of limewash is really just to wet the surface with the limewash and let it dry. It's quite different to painting: there is no tension between the surface and the paint, so can be applied very quickly. My final coat was applied in under 3 hours.