useing bonding on old or damp walls..

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oasis

oasis

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iv done this a few times i dont no how to finish s&c yet well have no experance in it. so when i come across old blowen or a damp wall iv done a waterproof scrach coat and then top coat of hard wall and then skim..do you think this is ok ? so far no call backs..what is the stuff i can get to kill the salts commin bk.

some pics of the last one iv done

useing bonding on old or damp walls..


useing bonding on old or damp walls..


useing bonding on old or damp walls..


useing bonding on old or damp walls..


useing bonding on old or damp walls..
 
mate if you can float bonding internally you can float s+c..
internals dont have to have a spanking finish on em, the main thing is flatness...
and if youve got the right amount of waterproofer in your scratch coat, your float coat will give you al the time in the world to float it up..
get it on, rule it flat as you can and walk away from it.. youll be a good couple of hours before you need to float it... depends on how much youve got on obviously but if its only one wall take a paper!! or go do something else..
youll know when its ready to float cos if you run the float over it and it brings water to the surface and 'drags' it its too wet, when its ready it floats up loverly.. just consolidates the surface nicely, what i normally do is float it flat with a normal float, then just wind the screws through a couple of mil and give it a light devil float...
the waterproofer in your scratch coat 'should' hold any moisture back but its not to be recommended cos if it does get through then the bonding will soak moisture up like a sponge..
the waterproofer with salt repellant/neutraliser in it is abtainable from chemical companies such as triton, sovereign etc.. whether or not theyll sell it to you not bein a registered damp proofer is another matter - https://www.triton-chemicals.co.uk/prodb1.php - trimix 1 is the one you want..
alternatively you could contact a local damp proofing company and see if theyll sell you a tub or 2
 
Dont use waterproofers in scratch coats in bathrooms in older buildings your asking for condensation by inhibiting the walls from breathing.
Lucius.
 
Eh .... what about the tiles and the bathroom paint that is %100 watertight that on these breathing walls ???

Rich
 
lucius said:
Dont use waterproofers in scratch coats in bathrooms in older buildings your asking for condensation by inhibiting the walls from breathing.
Lucius.
Click to expand...
new regs over here mate since about 2005.. every bathroom must have a run on fan fitted...
specifically for condensation..
condensation wont dissipate through porous walls anyway, it'll just meake em damp and youll end up with black spot mould.. commonly found in old houses on bathroom ceilings where thers hardly any insulation..
 
lucius said:
Dont use waterproofers in scratch coats in bathrooms in older buildings your asking for condensation by inhibiting the walls from breathing.
Lucius.
Click to expand...
interesting.....never heard that before..
 
Waterproofer only reduces the passage of water through renders it doesn't make it waterproof and it also does not block the passage of air
 
The regs for run on fans in the U.K. have been in force since the early eighties as far as i remember but personaly dont find them that effecient, waterproof paints are not asvisable in a bathroom a dehumidifying paint should be used, surely youve all seen condensation problems in fully tiled bathrooms in older houses with poor insulation and ventilation. A waterproof additive will not stop the passage of air it will inhibit it.
Lucius
 
Yes good article written by a double glazing salesman selling his wares but the truth of it is he is dead right and any competent tradesman should know all this anyway.
Lucius.
 
I have just re done my bathroom and had new double glazing, underfloor heating (the room is always warm), more insulation in the loft space and an 8inch vortice fan and i still get condensation. the best way to deal with it is to shower with the window open and the bathroom door wide open.

Rich
 
sbr oasis give it two coats mixed with cement to a brushable paste
 
Richard i tell my customers this in Spain, you can have the fan if you want but the only proven way is to keep the window open when showering.
Lucius.
 
I bought the best fan i could buy .....£100 ish and it still doesnt clear the steam fast enough,of course it must help but window and door kept open is the best way and probably always will be.

Rich
 
yea..wots the point in fixing a damp wall with out waterproofer ya might as well bond the hole wall otherwise?
 
Mate, whats the matter with you lot condensation is not damp its when the inside temp and outside temp come in contact and hit dew point and adding waterproofer wont make the slightest bit of differance in my opinion make it worse.
Lucius.
 
i think the origional question oasis was askin didnt really have anything to do with condensation.. it was more 'what to do with a damp wall'.. or did i read it wrong?
 
youll prolly get away with what youve done there by scratching with s/c+waterproofer but it aint a good idea mate..
like i said 1st post, if you can float bonding and youve already had the s+c on site, just top it with s+c and float that...
 
2 reasons one the walls needed to be built up like 4inch! old thick walls had to meet the skirting and window frame..and when ever iv done s&C i only get it on thin..plus iv just never finished s&c and dint wanna mess up a job for a nice customer..iv not got much experance with bonding out hole areas either..
 
use drycoat and dab it with mr boards mate ......or if youve already used s/c dab over that
 
iv done that one before found that some how damp got 2 the walls still...maybe that was just and unfixed damp wall dow.if u were just useing s&c i guess u would have ta build it up in like 3-4 coats?
 
yeh exactly mate.. ive done a lot of damp proof jobs where i had to build it right out but you can usually get it in the same day cos the bricks suck it up like nobodys business..
if you let the first coat 'cure' however, the waterproofer becomes 'active' and youll have to put little thin layers on...
get em while its drying but not cured and your ok..
 
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