This is a short post showing videos and photos of the Diathonite being applied. It was a busy three days. BorderLime worked really hard and did a superb job. We worked alongside them, with Tom on the mixing machine. You can see from the videos the speed at which the product goes on to the walls, and the mess it creates. It really was worth masking stuff up thoroughly, although we still spent several weeks vacuuming fragments of cork and lime dust.
The finished result was transformational. We’re yet to experience a winter with it, but I’ll post an update when we have some more feedback on its performance.
Videos of Diathonite Application
Diathonite Mixing Machine in action
Spatter coat application onto smooth substrate
Spraying the second coat onto the stone walls
Trowelling off the second coat
Photos of Diathonite Application
To read about how we decided to use Diathonite and how we prepared for the installation, read the other posts.
19 comments to “Diathonite Insulating Lime Plaster – Part 3, Installation”
Colin - 9th July, 2020
A great three posts on your application of Diathonite. Down here in Kent, we are about to embark on a retrofit of a Victorian house with solid brick walls – so similar enough to learn from your experiences, but also different enough that I can’t just apply them 1:1.
My question though is related to drying time – specifically, how long did it take your 50mm application to dry? I can see from Diasen’s tech specs that they claim 15 day’s drying time, but I can’t see what thickness that relates to. The question we are asking ourselves is – how long do we have to wait from application (60mm Diathonite + Argacem HP) coat before we can paint the walls?
Any insight you can share will be very welcome. Thanks,
George Harris - 14th September, 2022
How’s your insulation performing?
I’ve also got a wall covered in 0.037, but that was before I discovered the work of Nigel Copsey and David Wiggins. Wiggins and others research into NHL’s is shocking. Not only do they continue to strengthen over 1000 days (sometimes doubling their strength as compared to 91 days) but they also vary hugely in their actual strength, regardless of what the bag says.
It’s getting on for 2 or more years since yours went on, so I’m hoping the NHL 5 in our insulation is actually a weak one, and is offset by the volume of other good bits to aid breathability/moisture movement in the plaster.
PS. Can send a link or two if you’d like.
George Harris - 7th November, 2022
Please have a look at https://youtu.be/D8EOKzCLNi0
For a presentation on the benefits of hot lime. There’s a section in the video about NHL‘s, but for a longer presentation about the why and how of hot lime vs NHL or cement;
As I said, my co
George Harris - 7th November, 2022
(Dont know what happened there!) My concern is long term moisture movement.
Sadly I don’t know why your reply didn’t get to me sooner, I didn’t get a notification about you having done so!
Jon - 5th January, 2023
Great blog, thank you.
What kind of ground floor did you eventually install, and how did you address the issue of thermal bridging at the interface of the ground floor with your new diathonite walls please?
Jon - 8th January, 2023
Yes, very helpful!
Do you know of any fellow researchers that would like a project to collect data from in relation to interstitial condensation and thermal bridging, Lois?
If you do please email me their details.
Jon - 19th January, 2023
Hi again Lois, I’ve been doing a bit more research and a couple of things have come up that I’d be interested to know your thoughts on:
1. Using a DPM in your floor may force moisture horizontally along the underside of the membrane and into your walls. I got this from advocates of Limecrete floors that use a geotextile membrane below recycled glass.
2. NHLs (and Diathonite is using NHL 5!) not only have reduced porosity (compared to non-hydraulic lime plasters), but keep on hardening, so over time they act more like cement, trapping moisture, not allowing it to migrate out of the wall.
Anybody got definitive answers to these two possibilities please?
Richard Talbot - 30th January, 2023
Hi Lois, we have a very similarly constructed property to you just a little further north. Couple of questions:
Did you consider pro clima type membranes when discounting use of wool / stud-walls / woodfibre board and I assume you were looking at to be used in addition to diathonite?
Do you have any knowledge whether hand applied diathonite is as effective as machine applied? Contractors seem impossibly busy and also we may not have budget to use professional – despite the speed of application being so attractive
Karl Roscoe - 30th August, 2019
Great stuff, thank you once again for sharing.
In the picture ‘Finished top coat and the join into stone wall…’, regarding spray the ‘left’ wall, is the ‘left’ wall partly external or completely internal? I’ve been thinking about spray diathonite three inches into a room on the internal wall that meets an external wall? Your left wall looks like at least a couple of feet and so interested to know the reasoning there.
Where did you apply the Deumix? In for the first foot up a wall where rising damp was an issue, then continue with Thermactive or Evolution?
LoisLogsLune - 17th September, 2019
Thanks for your question. The wall in that picture is in fact the external gable wall. In a yet-to-be-published post, I will explain the detailing of the gable, but in summary the gable had a new stone wall built on the outside of it, and a fully filled cavity using Dritherm. So whilst this wall is now insulated, there is the thermal bridge between the “external” insulation in the gable, and the internal diathonite (see the detail in the sketch http://luneretrofit.com/diathonite-insulating-lime-plaster-part-2-detailing-and-preparation/).
We returned the diathonite approximately 1m along the gable wall. I suspect that 3 inches won’t really provide much benefit, but our 1m corresponds to the purlin above, so was a natural place to take it to.
The Deumix was applied to two areas for the first 1m height on the external back wall of the property which is actually below ground level outside (albeit with external insulation, tanking and suitable drainage). Whilst these were not specifically “problem areas”, both were in corners under the stairs, and so had limited air flow. The carpets which were there were mouldy and smelled bad, and there was a general sense of dampness. Whether this was rising damp or just stagnant air in a cold corner is difficult to say, but we took the opportunity to apply the Deumix whilst doing the rest of the work.
When we returned from a recent trip away, for the first time since we’ve owned this place, it didn’t smell musty when we returned, so I reckon the Diathonite is offering a benefit already.
Hope this answers your questions.
Plastering Auckland - 8th May, 2020
This is a short post showing videos and photos of the Diathonite being applied. It states about diathonite insulating thermactive lime plaster application and installation . Thanks for this amazing article. Great blog indeed, will visit again future to read more!! You must also check out qualityplasterers.co.nz it has some great insights too.
Geoff Bolam - 13th May, 2020
Hi Lois, Thanks for posting the article.
I’m considering Diathonite for the conversion of a small church to a holiday let.
We have similar problems of damp in the walls – caused by a modern concrete floor and damp-proof membrane, cement pointing, leaky gutting, no heating, etc.
We were initially advised to dryline the entire building but this rejected on conservation grounds, and then to just remove the cement pointing and repoint and repair with lime.
However, we’re going to have to work hard to heat the building as the roof cannot be insulated much either, so now looking at insulated plaster at it appears to offer a solution both issues.
I’ve been looking at Diathonite but our architect is cautious about using a ‘modern’ material in a historic and about the longevity of it.
I just wondered if you’d experienced any issues, such as cracking, performance, decorating etc, since having it installed?