I would very much doubt it!!

A few on here might have, no need if you wet plaster though.

No, I seal the ends of the channel with acrylic sealant, only parge behind the boxes

http://www.ecomerchant.co.uk/liquid-blowerproof-brush-paint-on-airtight-sealing-membrane-5kg.html

Product Name Price Qty Subtotal
Subtotal £49.99
Shipping & Handling (Ecomerchant - Courier) £15.00
Tax £13.00
Grand Total £77.99

How is that comparing with sealing tape? Coverage they say is "One 5kg tub will cover approximately 83 linear metres at 75mm wide."

I think ecomerchant used to sell this as 'airtight paint' in case anyone else does a search.

Got the dregs of a tub of this from a friend. I think it's mainly SBR (around £20 for a 5 litre container typically), the smell is identical. It has some fibres in it, which seem to melt readily so I suspect are polypropylene or similar (used for screeding, I had half a bag in the shed to compare with). The MSDS also says it contains aluminium hydroxide.

I found this research paper abstract - https://www.researchgate.net/publication/229537123_Decabromobiphenyl_oxide-aluminum_hydroxide_system_as_a_flame_retardant_for_styrene-butadiene_rubber - where it was investigated as a flame retardant, but also had the effect of making SBR more flexible. Another patent online describes car tyres with sbr and aluminium hydroxide, so I assume its long term stability is fine.

The MSDS also mentions 5-chloro-2-methyl-4-isothiazolin-3-one - which seems to be an antibacterial / antifungal, and is used in some other SBR products (it shows up in their MSDS too).

I've ordered some aluminium hydroxide, so will try mixing something up when it arrives and report back.

IGuess you could use something like brush-applied Aquaseal - flexible and waterproof, so also airtight...

Hi all, does anyone else have any comments on this product? Thinking about using it myself as it looks very useful

Thanks

Gervase, formerly of this forum writes:

We ended up using blowerproof all over the place (on an EnerPHit refurb) and in many situations it really is a lot easier and probably less expensive than tape.

We did use in chases and it seemed to work very well when tested with only a couple of tiny leaks. The logic behind using it there was that whilst the wet plaster will cover the chase you can be left with air path into cable exit/entry points.

We also used it around joist ends in conjunction with a non-shrink grout. MUCH easier than tape and certainly effective.

Be aware it is very sensitive to temperature and moisture content of substrate in going off. In some cases the first coat took several days to go off.

I’d certainly use it again.

This is interesting; just recently I've been wondering about covering the entire house in this stuff (using existing render as air barrier then EWI over the top), simply because I don't trust S+C parge coats (with joins, different ages etc) for long term airtightness.

You can get it in spray form; even so I can imagine it would be expensive.

Posted By: kmachIs there a difference between Blowerproof products and normal bitumen?

Yes, they're nothing like the same.

https://www.ecomerchant.co.uk/liquid-blowerproof-brush-paint-on-airtight-sealing-membrane-5kg.html
"VOC free, water based, flexible, fibre reinforced, polymer"

https://en.wikipedia.org/wiki/Asphalt
"sticky, black, and highly viscous liquid or semi-solid form of petroleum"

Posted By: wookeyHowever I also don't find it as reliable as tape. e.g. I painted round the plasterboard where a loft-hatch had been moved (The joints had already been filled with acrylic goop so there was a reasonably flat surface to deal with). I just did some airtightness tests and there were quite a few blowing holes in the blowerproof. Even after a 2nd coat one remained. 3 coats did the trick. The gaps were not at all obvious to the naked eye and so were small, but I had previously assumed that if it looked painted then it was probably actually airtight. That's not true.

I haven't used it, so I just have questions :( Does the manufacturer supply instructions about how it should be applied, and did you follow them if so? (sorry, I don't mean to be rude in asking) And following on, have you asked them about your experience and what might have gone wrong? On a different slant, they advertise the Imperial War Museum archive (I think) as a reference; I wonder if there are any accounts of the technique used to apply there?

With tape, so long as it is done carefully, the substrate is clean, it's actually stuck down, and not 'bridging' at corners, it's totally reliable.

In the case of a concrete substrate they do specify to apply a primer to the surface first and I was religious about doing that. It all worked well at the time, maybe I'll do another airtightness test at the ten year mark? (anybody want to crowd fund it? :)

Posted By: wookeyIt does say there is a technical datasheet that I should consult. I've not done that.

Colour me surprised It seems the datasheet is available on line https://www.blowerproof.co.uk/wp-content/uploads/2017/05/Blowerproof-Liquid-Brush-Data-Sheet.pdf and it does say "Apply in two layers, the second layer after complete drying of the first layer. Total advised indicative consumption: 0.5 - 1 kg/m2." There's also https://www.blowerproof.co.uk/wp-content/uploads/2017/05/Application-Guide-Blowerproof-Liquid-Brush.pdf with more detail. It says to fill gaps with their mortar (or similar) but doesn't say anything about movement that I can see. It might be notable that the PHI component certificate includes "Self-adhesive Tape „Butytape”" alongside the Blowerproof itself, but it doesn't explain why.

Stairs are an interesting problem, particularly for retrofits. In our case we made sure the airtightness layer passes uninterrupted behind the stair stringer. The stringer is just supported at the top and bottom and there's a bead of sealant between it and the wall. It looks fine without any noticeable cracks but I'm glad its not part of the airtightness layer. I can see airtightness must be a lot harder to arrange in a retrofit. Removing the stairs just to ensure airtightness behind them sounds like a lot of disruption. I think unless Blowerproof answered a direct question about how to use it to seal that specific junction, I would use [deliberately lengthwise slack] tape along the junction in the conventional way. Then beading of some kind over the top to cover the tape.

Where the first floor joins the airtightness layer there had to be penetrations of course. So we used black plastic DPM as the airtightness layer there, joined to the plaster elsewhere with Contega palster-in tape. Then we attached the floor using ledger beams connected to the timber ring beam in the wall using coach screws and drilled through squares of double-sided adhesive butyl tape to ensure airtightness around the bolts. (that was an electric drill job!). We did that to avoid all the complicated sealing around joists and joist hangers. Again a lot easier in a new build.

I think it's brilliant. A life saver in retrofit situations where you don't always have the benefit of being able to plan everything, e.g. It gets you out of situations when there wouldn't be enough space for tape, and it's a great all rounder for things like service penetrations.