Thermalmix - Insulating Paint Additive 3 for 2 Special Offer (Get 3 Bottles for Price of 2)

I was very dubious to begin with as to whether this product would actually work. I read the reviews people left on here and wondered how genuinely "true" they all were. But as it was only £15 for a bottle (or £40 for a bundle of three) I decided I haven't got too much to lose so decided to buy a set of three and give it a try. I mixed each bottle with 5 litres of paint as instructed and gave the ceilings in my bedroom and lounge three coats applying it liberally and then a final coat of just paint to colour and smooth it back over. It originally left a bit of a sandy texture so wanted to keep the ceilings looking as before. After applying the three coats in my bedroom and lounge, I can categorically say it has definitely taken the edge off the cold temperatures in the rooms during the winter months and would say it has reduced the heat loss by around 15% to 20%. With all this said, if you are looking to properly insulate your rooms (not to mention the loft) it in no way replaces the conventional form of insulation using fibreglass and other professional materials. But if you're after something that's DIY friendly which doesn't require major work involving drilling and lot's of dust, it's well worth considering providing you don't mind the tedious task of painting your ceilings multiple times!

It's good. It makes the room warmer. You can feel the difference if you put your hand on a wall where this stuff has not been applied. You need to mix 5 letters of paint with 1 bottle of this stuff. Then give the wall 2 coats. When dry it will feel like sand paper to touch. It's not a problem but if you don't like the feel then give the wall another coat without this stuff mixed in. It does not change the colour of the paint.

I bought this additive to use in white paint for my bedroom that had been very hard to heat. I only moved into the house in January 2023, it’s an old stone cottage that’s over 200 years old and had been empty for nearly 5 years - so no cavity walls or any easy way of insulating the rooms. I have smart thermostats on the radiators so can read the room temperature, it never got above 14.5c in the front bedroom no matter how long the heating was on for. I wanted a quick solution as I plan on doing a lot of work in the next year but couldn’t bear the cold and keeping the gas central heating on was costing a fortune. I thought this was worth a try, I only painted the walls and didn’t do the ceiling. It’s not difficult to mix into the paint, I would recommend a drill attachment as it makes it much quicker. Two coats of paint later and there has been a dramatic improvement in the heat, the bedroom is reaching 19.5c most nights without any extra heating time. The room is actually comfortable to sleep in now and there is no chill in the air, as before it was unbearable at times. I am really glad I tested this stuff and am now planning to use it in the final paint when the building work is finished, I am painting the ceilings and all walls when finished. I am also looking into putting it on to the walls in the utility room before it is tiled. I can definitely recommend you give this a try.

I have used this in a previous house to help insulate a cold bedroom that condensated badly. It mixes with 1 bottle per 5L of paint and fininshes with a gritty texture to any of the paints (gloss/silk/matt) that it is mixed with. Applied in 2 coats it definitely does as described and makes a temperature difference compared to untreated parts, the change is minimal but noticable to the touch. I applied 3 coats along with a 4th with added ant-mold top coat. Never had condensation or mold in that room again. When mixing it does increase the volume of the paint so make sure you have a large enough container when mixing it in. The reason for 3 stars: The first single pack of this I ordered was smooth and easy to pour from the bottle, it was like kiln-dried sand and mixed easily and evenly with the paint. 5 stars for this one. This tripple pack arrived but the contents were clumped together like damp sand, as if it had not been dried out properly before shipping or stored in damp conditions. DO NOT MIX WITH PAINT IN THIS DAMP STATE. It must be dried out before use, else it will clump up and leave unmixed stony blobs in the paint that then leave grey blotches on the walls. Otherwise a superb additive to assist with insulating cold walls against condensation.

Brilliant service and quality products

This is crap ive got more mold than ever before

I’m rating this based on ease of use - not if the product works or not as it’s too early to tell being summer. Other reviewers have testified to it being very effective. Here’s my experience so far. I mixed 5L of a cream coloured high quality acrylic paint in a 10L bucket with the additive. I used a paint stirrer electric drill attachment - which made easy work of it. I added about a quarter of the additive bottle in water as a guide. I think you could maybe add half a bottle - but beyond that your mixture would be too thin. There was no discolouration at all. The applied paint perfectly matched a previous coat of the same paint without the additive. I used a paint pad to apply with no problems at all - it’s very slightly thicker - but it’s not noticeable. The finish is good. Some reviews say it’s a rough finish. That’s not really correct - it’s only rough from a tactile/touch point of view. It would be hard to tell visually. Bear in mind you are adding fine silica - so the finish to the touch is a bit like very fine emery paper. If this product actually works as well as some reviews state - I would highly recommend it as it’s very easy to use as long as you mix it properly. I will be adding it to all my wall and ceiling paint from now on.

I don't know what happened with the packaging size, but now you get 3 of these on photos, compared to one I ordered before (about same price but for 3 big ones you get 3 little ones) . Anyway, I feel tricked a bit. Same thing, same quality, was working good before, it works the same way now. Whatever, it's still good product!