wall advice

[brinkley]

Hello
Probably for the plasterers here .
i have a wall which is very holey
what is the best way to render this so i can paint the other side without water getting throgh the wall and ruining the paint as seen in the pictures

[brinkley]

come on do i have to seal the crumbly bits first .mixes and ratios

[whitebeam]

Is the stone work held together with a lime mortor

[brinkley]

not too sure all i can say is that it is crumbly and white probably around 25 years old

[brinkley]

actually looks older then 25 years so could be 35 -40 years old

[whitebeam]

If that is a stone then a lime mortor probably would have been used, if you put a render on that you may find it cracks due to the movement of the lime.

It looks if a sand/cemnt render has been applied to the other side you want to paint, so moisture gets through on the stone side and the lime allows the moisture to evaporate but the render holds the moisture behind it because it's to strong a mix to allow any evaporation.

Mind you the copings on the wall don't seem wide enough and water could also be creeping behind the render.

[brinkley]

can i fill the holes ? if so what with.
can i put that metal sheet stuff over it (the one with the holes in)epm or something then render over that?

[whitebeam]

You would'nt be able to fix anything to the the lime mortor, it's to soft and friable and if you fix the eml to the stone they may not be well fixed into the lime.

There,s alot of weight with the amount of render your'll need to fill the holes and make it look flat.

Is this a job your pricing for someone

[brinkley]

im pricing it for a hotel i do a lot of work for basically it dont need to be flat on the stone side just waterproof because its only a trade entrance but the other side (white side ) looks out to the carpark they need it so that the paint doesnt flake and peel off and look an eyesore.

[TF Ed]

theres a lot of work in that wall, it aint an easy one!!!!!
as mark says, lime mortar is soft, plenty of dubbing out. there alot of hacking and prep work there mate and it really needs an inspection imo before you can gauge mixes and mechanical keying

ed

[brinkley]

and the paint is like that because water is getting through the wall from the rough holey side.

[brinkley]

could i not put some kind of sealer in the holes and plug them up

[whitebeam]

Like I mentioned about the coping stones the joints on them could be letting in water through to the wall because the sand/cement may have perished and they ar,nt wide enough to allow the water to drip away from the top of the wall.

Perhaps a breathable resin paint, if there is one for the flat rendered side

[aqua blue]

For what it is worth. I would wire brush, brush on a stabiliser, fill holes with rapid set adhesive then waterproof wall with weathersheild. Unconventional I know.

[brinkley]

if i try and wire brush it i might end up brushing it all out

[mikethetile]

For what it is worth. I would wire brush, brush on a stabiliser, fill holes with rapid set adhesive then waterproof wall with weathersheild. Unconventional I know.

how does that solve the problem of water ingress

[brinkley]

confused.com

[mikethetile]

I can understand the problem you have with water coming through the rear of the wall and bubbling behind the paint till it blisters and blows

the render should never have been painted but now it is it needs repainting

the problem is water sealing a structure that is built to absorb water and evaperate it from the surface

[brinkley]

exactly mike

[brinkley]

i could cover over with wedi board

[mikethetile]

there is a paint for this situation , im trying to find it

im sure its made by johnstones

[brinkley]

glimmer of hope

[aqua blue]

A 'flexible' adhesive.

[mikethetile]

I cant find it on their website, ill ring their tech dept tomorrow

[brinkley]

your a star mike cheers

[mikethetile]

no wonder I couldnt find it on johnstones site, Its a sandtex product

sandtex make a breathable masonry paint, you will also need the bridging primer as the walls already emulsioned