Keiths 32" build in north yorkshire uk

[S1MON]

Re: Keiths 32" build in north yorkshire uk

simon, heres a link here to the spec of the product used https://www.promain.co.uk/specsheets...20UK%20PDS.pdf

it was basically just painted on with a paintbrush nothing fussy, when it's used on flat roofs you normally apply in two coats with the first coat having fiberglass remat in to strengthen, but as i only had a couple of inch of stuff that was left over mines only had one good coat. where are you up to with your oven? are you looking for a waterproof finish? a few people in the uk have used k rend that might be worth checking out.

That's great thanks Keith. I'm at the planning/deciding what to build stage

I originally thought I'd go for a 'doghouse' style oven, but the igloo type ovens are definitely growing on me, and the finish you used really stood out. So much effort is spent drying the ovens, the last thing you want is our soggy weather spoiling things when your back's turned. I've heard of K-Rend as well, but not checked that out yet, it's a way off ATM to be honest.

Thanks again, Simon.

[kstronach]

Re: Keiths 32" build in north yorkshire uk

Hello there Keith,
Also wondering what you applied before the membrane? Looks like stucco but you were able to put it on in a really smooth fashion? When I put mine on it was so cement like that it was very hard to work with. I would like to tile my dome and need to smooth out what I have with one more layer to then lay tile on.

Any input you have will be greatly appreciated. Nice build.

Question, will that membrane melt if it gets above 90 Degrees? If you meant Celsius then it will likely be fine.

hi darin, cheers.

yea its just stucco, the scratch coat was mixed at 3-2-1. 3 parts building (soft) sand, 2 parts sharp sand, 1 cement and some waterproofer, an additive for cement which acts as a plasticiser and retarder and makes it easier to apply, if you can't get hold of this don't worry a little squirt of washing up liquid will help.



then for the top coat i mixed it at 4 -1 with 4 parts render sand ( like building sand but a little bit grittier) 1 part cement and again some waterproofer and a cup of SBR (or PVA) bonding additive which just improves adhesion of the mix. both these coats were applied with a handboard and plastering trowel, you want the mix not too stiff but then again not too wet! if you're mixing with a cement mixer let it mix well before going too mad with the water, too allow any water to come out of the sand and let the waterproofer (or washing up liquid) do its job.

damp the scratch coat down before you apply the top coat, in your case (i'm assuming you already have a coat of not scratched stucco applied) i would paint it with SBR or diluted 2 - 1 water and PVA to seal and prep the surface for your top coat.

then when its on shape as best you can with the trowel and then leave until it starts to set abit, then rub it up with a dry sponge in a circular motion it will smooth and fill any hollows etc. you'll have to play this part by ear its just about catching it right, in the UK on a cold day this can be 5 -6 hours later but in summer might only be 1 hour! if its too wet it will drag too much but too dry and you'll struggle to rub it up well. depending on your climate (if its really warm) you might need to sheet after applying to stop the sun drying it out too quickly, and then when you have finished, mist it down with a garden hose periodically.

this was the top coat when it was finished and rubbed up




then when i swapped that stupid single wall flue out for the insulated flue i domed up some strong vermicrete with sharp sand in around the chimney, 1, to hold it and 2, to stop and excess heat that you get in that area affecting the membrane i put on

vermicrete around new chimney



yea the membrane's service temp is 90 deg celsius so i should be ok, it got reasonably warm once when the oven was damp and it didn't bother it but normally the outside of the oven barely gets warm, in winter here its cold and in summer get slightly warm but can comfortably keep your hand on it

hope this helps

regards

keith

[kstronach]

Re: Keiths 32" build in north yorkshire uk

Can you give more info on this, like which specific product it is, and how to use (if it's fussy). It looks like a great product, but the sika web site I found is just awful.

Thanks in advance, Simon.

simon, heres a link here to the spec of the product used https://www.promain.co.uk/specsheets...20UK%20PDS.pdf

it was basically just painted on with a paintbrush nothing fussy, when it's used on flat roofs you normally apply in two coats with the first coat having fiberglass remat in to strengthen, but as i only had a couple of inch of stuff that was left over mines only had one good coat. where are you up to with your oven? are you looking for a waterproof finish? a few people in the uk have used k rend that might be worth checking out.

[Novaslo]

Re: Keiths 32" build in north yorkshire uk

Hello there Keith,
Also wondering what you applied before the membrane? Looks like stucco but you were able to put it on in a really smooth fashion? When I put mine on it was so cement like that it was very hard to work with. I would like to tile my dome and need to smooth out what I have with one more layer to then lay tile on.

Any input you have will be greatly appreciated. Nice build.

Question, will that membrane melt if it gets above 90 Degrees? If you meant Celsius then it will likely be fine.

[S1MON]

Re: Keiths 32" build in north yorkshire uk

i covered in sikalastic which is basically a system we use at work on flat roofs

Can you give more info on this, like which specific product it is, and how to use (if it's fussy). It looks like a great product, but the sika web site I found is just awful.

Thanks in advance, Simon.

[kstronach]

Re: Keiths 32" build in north yorkshire uk

never put up a finished photo so i thought i better had!

i changed the single wall flue for a insulated flue and rendered her up, then when i was sure she was bone dry i covered in sikalastic which is basically a system we use at work on flat roofs its is a single component, cold-applied, moisture-triggered polyurethane membrane. It cures to form a seamless, durable and weather resistant waterproofing solution for exposed roof areas. its flexible to and has a service temperature of 90 degrees. do you guys over the pond have anything like this?

[rsandler]

Re: Keiths 32" build in north yorkshire uk

Glad it worked out for you! Clearly you are handier with stucco than I. Looks good.

[kstronach]

Re: Keiths 32" build in north yorkshire uk

hi rsandler, just read your message, after cracking on tonight and meshing and stuccoing! tbh it wasn't too bad although i put quite alot of sharp sand in the mix which probably made it easier!!





got the flags bedded on round the oven tonight too so all thats left now is the final stucco coat!

[rsandler]

Re: Keiths 32" build in north yorkshire uk

I'd strongly suggest putting just a thin layer of vermicrete over your blanked before stucco-ing, even if you don't need it for insulation. I did stucco right over the blanket and found it to be a huge pain. Your blanket will be lumpy in places where the layers overlap, and stucco is a pretty terrible material to smooth those out. You'll get a better finish with a vcrete layer first. 'Course, you'll probably get a better finish than me anyway, because I am pretty lousy with stucco!

[kstronach]

Re: Keiths 32" build in north yorkshire uk

Hi yes building an igloo but no vermi going on. Stucco next straight over blanket.

[boerwarrior]

Re: Keiths 32" build in north yorkshire uk

That sure is an interesting flue!! It doesn't stop the airflow too much?

Wait a minute - is that blue sky I see in the background? I thought you didn't get any of that over there!

Very nice fast progress you have been making!!

[Greenman]

Re: Keiths 32" build in north yorkshire uk

Keith - I used chicken wire and it worked fine. It held the vermicrete until it set. Once that is in place the subsequent layers are easy/easier. I assume you are buillding an igloo.

[kstronach]

Re: Keiths 32" build in north yorkshire uk

a couple more updates . . .

got the flue set in place now. i shuttered the gap in between my front and back arch and filled with a mix of sharp sand vermiculite lime and cement angled into the flue.



tonight i have insulated the dome, not as bad as i thought it was going to be! i ended up cutting triangles out and the pinning back together with bits of wire, worked rather well! ive got 4 inch of ceramic blanket, the last layer is abit patchwork in places and i had to use a little bit of rockwool to finish off as i had used every scrap of the CB!

next step is mesh it over then get a render coat slapped on! went to the builders supply today and got a roll of chicken wire. i thought this would be easier to use on the dome than the proper expanding metal, however the exp metal is thicker gauge so the render has more to get hold of so to speak so i may now go back and get some of that instead! what mesh did others use and did it work ok?

keith



ps . . i know its not the most attractive flue but it was free so that works for me!!

[SAGGY470]

Re: Keiths 32" build in north yorkshire uk

Looking good, new to the forum and trying to ind som uk guys to get more local ideas

[Sharkey]

Re: Keiths 32" build in north yorkshire uk

Nice looking dome for hammer and bolster cuts only.

It could probably be called 'old-school'. I like it.