Fibreglass meshing with sand/cement

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Carltheplasterer

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To cut a long story short, I'm subbing for a builder that needs me to do 200 m2 of render, I told him ocr with mesh will be best bet as brickwork is in a bad state, then he dropped the bombshell that he didn't have money for OCR so I said I would see if I could prime the substrate and do it with s and c and lime, I have already fixed all beads (10mm) ready for application of OCR as per normal and was wondering if anyone knew what may be the best mix for this as I've spoke to a few old spreads who say I can't do it (and berated me for even attempting it this time of year lol) all input would be a massive help............
 
its not a good time of year for it weve just finished our last outside job for the year 2 huge gables and yesterdays one we had to finish rubbing up today and todays one took forever to go off had it all on and ruled by 10 diddnt start floating till 3 luckily there 3 of us and a lab following with the sponge
 
Solid through, engineers I think, but some of the faces are blown, had my labourer get rid of any loose bits, right on the sea front as well so the north sea fret is howling
 
SBR it and 2 scratch coats. 1st waterproofed and the 2nd tight coat without. Let it dry out and you will have a bit of suction and initial 'grab'. if there is to much suction spray water on with a brush not a hose pipe.
 
Rigsby said:
SBR it and 2 scratch coats. 1st waterproofed and the 2nd tight coat without. Let it dry out and you will have a bit of suction and initial 'grab'. if there is to much suction spray water on with a brush not a hose pipe.
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I need to make s and c and lime as close to OCR as possible, I was thinking 6-1-1 plastering sand- cement and- lime, what additives would you use?
 
A bit awkward using lime with a waterproofer. One counteracts the other. I have only used lime with a basic no gimmicks waterproofer like Pudlo. Feb used to make Febproof but recently it has become Febproof+ with the addition of an air entrainer. I haven,t seen it recently since Everbuild took Feb over. So I cant advise using lime with a waterproofed as I never mix the two unless it is a basic waterproofer if you can find one. As for the other coats use an air entrainer (plasticiser) like Febmix with your sand and lime mix. Less chance of cracking.
 
Would you prefer to use lime than a plasticiser? Im up north so I figure the least amount of water to possibly freeze the better?...........
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Carl OCR shouldn't be applied at 10mm for external work anywhere and from the sound of the location it should be as Rigsby has said three coat work with a finished thickness of 20mm. As said before forget about lime in your first coat and forget about trying to make your S&C just like OCR. To be honest the questions you're asking make me think you shouldn't be tackling such a job to be honest.
 
No, use SBR over the knackered bricks as a slurry coat. Whilst wet apply the render. I used 6;1;1 once and it cracked so now it is with Febmix. Very fatty with the two (lime and febmix) and lower water content. Can you get BLI cement up your way? I use BLI (Buxton Lime Industries) Limebond for the top coat prior to tyrolean. It has 20% lime already in it and plasticiser added. When I last enquired about adding a waterproofer they said on a basic one like Pudlo if you can still get it. Not one with plasticisers added as there is a full dose pf plasticiser already in it. if you do get Limebond remember it is 80% cement content.
 
I think OCR has latex in it (sbr) that will make it stickier. If you can afford it put some sbr in instead of febmix. I have used s&c with sbr and its well creamy but costs. 2.5ltrs of sbr to a mixer full of gobbo.
 
My guess is that if the builder doesn't have enough money for 10mm of OCR he isn't going to want to pay for the job to be done properly anyway.
 
essexandy said:
Carl OCR shouldn't be applied at 10mm for external work anywhere and from the sound of the location it should be as Rigsby has said three coat work with a finished thickness of 20mm. As said before forget about lime in your first coat and forget about trying to make your S&C just like OCR. To be honest the questions you're asking make me think you shouldn't be tackling such a job to be honest.
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Im not talking about monocouche/weber pral, and I've done a couple of jobs using weber OCR with fibreglass mesh at 10 mm and its fine, I was just wanting to know wether I could do it with s and c, quite happy sticking a tight scratch on etc and am aware of all the pitfalls especially this time of year so please don't think I'm a novice, just a question that's all
 
Chances are they will opt for an acrylic anyhow in which case I'll probs bang a tight coat of maite monocomposant over the top before the acrylic if it looks wank:RpS_lol:
 
Sorry Carl I was really trying my best not to appear rude (as I don't know you) but I don't care how many times you've applied 10mm of OCR it just doesn't come up to spec. It isn't a miracle product, it still needs to be 16mm in sheltered locations and 20mm in exposed areas.
Don't be like so many chumps (not calling you one) on here and ask a question, get good straight forward advise and then because you don't like the sound of the answers start arguing back that you know better.
 
I think the question has been answered no. Lol
thanks for all your help guys especially rigsby, this world needs people like you in it, the never say die optimistic attitude is what made British plastering the best in the world so thank you squire
 
Carltheplasterer said:
Chances are they will opt for an acrylic anyhow in which case I'll probs bang a tight coat of maite monocomposant over the top before the acrylic if it looks wank:RpS_lol:
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I hope the walls are well covered against the rain. It will take at least a week for acrylic to dry. Consider the cement based option read my thread SAS mineraltex. Marmorit SP260 or SPS graniman might be safer. Needs a coat of equalising solution but paint dries in 6 hrs.
 
Essex andy you are right, just times are tough at home and need the money didn't mean to make a nob of myself, just got caught up on the idea, 6 old time spreads told me this before I came on here but I wouldn't listen, was hoping to find a magic formula, thanks so much for the advice mate.
 
Rigsby said:
I hope the walls are well covered against the rain. It will take at least a week for acrylic to dry. Consider the cement based option read my thread SAS mineraltex. Marmorit SP260 or SPS graniman might be safer. Needs a coat of equalising solution but paint dries in 6 hrs.
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Going to cover the whole scaffold in waterproof sheeting and have hessian cloaked over after every part, u r a total legend mate thanks so much, will have a look at threads now mate
 
If the job is covered up against the rain then temperature to one side do it. if it is not covered the client will put you under pressure to get on with it but it is sole destroying to turn up to find the walls soaked or the bleeding stuff wont go off and it's getting dark. Do two walls and one turns out good the other scoured because it was to wet to rub up and thats a good excuse not to pay you! The difference is there to see and explaining it was down to not going off will not wash, it their get out clause not to pay.

I would stick to sand, cement with Everbuild CF Zero in the mix. Accelerant, frostproofer and plasticiser. make it go off.
 
Carltheplasterer said:
Going to cover the whole scaffold in waterproof sheeting and have hessian cloaked over after every part, u r a total legend mate thanks so much, will have a look at threads now mate
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Get debris netting instead. hessian gets wet but 2 layers of debris netting will stay dry.

You need 3m deep netting but some of the bigger scaffolding co's might have some secondhand to sell. I usually buy a 50m roll about every 3 years and it gets used all year round. keeps the rain, sun and wind off. Not expensive either. About £80.
 
I have bucket loads of sbr, the bulk of it is in 35m2 sections (roughly) which me and my labourer can smash no worries, (1 a day), so if I prime with undiluted sbr, have the mesh cut to size and ready and use the cf zero do you think it is possible to get it done in one?
 
its hard to get mesh into sand and cement scratch coat as it takes up to quick to allow the mesh to be embedded... also you cant put sand and cement on at 10mm thickness 5mm each pass as it will be fcucked...

Tell the to$$a to fcuk off and wait until he can afford it
 
Render Systems said:
its hard to get mesh into sand and cement scratch coat as it takes up to quick to allow the mesh to be embedded... also you cant put sand and cement on at 10mm thickness 5mm each pass as it will be fcucked...

Tell the to$$a to fcuk off and wait until he can afford it
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Looks like base coat all the way then! I knew you would catch me on here!, should have just listened to uncle steve and saved myself the trouble, what a hoot xxx
 
Render Systems said:
its hard to get mesh into sand and cement scratch coat as it takes up to quick to allow the mesh to be embedded... also you cant put sand and cement on at 10mm thickness 5mm each pass as it will be fcucked...

Tell the to$$a to fcuk off and wait until he can afford it
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I embed mesh in S&C scratch coat all the time Steve without any difficulty. I still wouldn't try and do this job in one coat though, not a chance.
 
If hes being a tight arse and just wants it doin, do a scratch coat with mesh at 4mm and mix 4-1 sand cement but for the liquid use 50/50 water to sbr, this will stick to anythin so be sure to clean your tools, then top with 5-1 sand and cement and 70/30 water/sbr, the sbr content will ensure the product never cracks or blows and there will be no need for surface prep, i have used these mixes and not had any problems in fact with the sbr in the scratch you can apply as thin as 2mm with no probs be sure the sand is dry and not from outside full of water as this will weaken the mix, wickes keep theirs inside
 
If he wants 10mm of render and has refused to pay for OCR just put ten mm of sand cement on **** him, if you've given him the spec do what you have to do and charge him if hes given you the spec **** him ask him what he wants then
 
4mm mesh is a bit small for S&C, the sand I use anyroad. 5mm at least I pref 8mm from L&D olive in colour. 210g.

For the sbr I use a slurry, neat sbr mixed with cement to a brushable slurry. You have to be quick with the mesh as a bit of suction and it is difficult. If you 3 coat it you have more chance on the 2nd coat. As for 1 coat in the day then no I doubt it.
 
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