Crumbling Brickwork below Rendering All manner of questions and solutions to problems and issues surrounding the subject of brickwork, blockwork and stonework

[feisar]

Hi, after the winter the bricks at the rear of my house have started to crumble, I guess its the damp getting in, freezing, then thawing, they have done it before but not as bad as they are now. With the weather getting warmer I now feel its time need to address the situation as they are in quite a bad state.
Last year I tidied up the drainage on the back wall.
What action you think should be taken. I am a complete novice but dont mind having a go. I fear this is going to be expensive if I get someone in.
I was was thinking repair the bricks, re-point and seal with some kind of bitumen. Any help would be much appreciated. Thanks in advance
Darren

[welsh brickie]

I would fit a metal bead called a (bellbead) around the house just above the blown brickwork this throws the water away from the wall.then plaster the brickwork with a waterproof addative and paint it with bitumin to seal it for good measure

[feisar]

Thanks welsh brickie, glad you didnt say the bricks need replacing or something worse, phew :)
So I would start with the bell bead below the rendering on the brick or on the rendering itself?
Do I need to repair any of the bricks?
And you say plaster the brickwork with waterproof additive, have you a product in mind so I know what to purchase? Same with bitumen seal please. There is so much stuff on the market, I'd end up getting the wrong thing.
Thanks

[welsh brickie]

ok, hack the plaster off to about 100mm above the brickwork and fix the bellbeads to the exposed brickwork with galvanised nails.Make sure they are level.
Paint a mixture of pva solution and paint all exposed brickwork.
Then mix 4 sharp sand 1 cement and waterproof addative with 1 hydrated lime together in either a mixer or wheelbarrow and render over the mesh to the original render.
You will need 2 coats, the first coat will need to set as its quite thick.this is called the scratchcoat,while the render is drying you can use a nail to scrape lines in the render,this will provide a key for the second coat.
The second coat is the same mix as the first without the addative,To match your house render take your time and level your render as much as possible and use a damp sponge on the render to smooth out the area.
below the bell bead try using either a sponge or 3inch wet brush to make you finsh.Once set paint below the bellbead with a buitumin paint.

The waterproof I use is 1 shot rendermix addative but ask your local builders merchants they may have another in stock 5lt is enough

[feisar]

Thanks, I'm a little unclear on a couple of points, sorry for being a nuisance.
So I fit the bell bead, paint a pva mixture on all brickwork under the render or just the bit I have exposed? Can I buy that pva mixture or do I make it up?

Mix 4 sharp sand 1 cement and waterproof addative (is this the 1 shot rendermix, how much of this?) with 1 hydrated lime together.

Thanks for your patience.
Darren

[welsh brickie]

[quote="feisar"]Thanks, I'm a little unclear on a couple of points, sorry for being a nuisance.
So I fit the bell bead, paint a pva mixture on all brickwork under the render or just the bit I have exposed? Can I buy that pva mixture or do I make it up?

Mix 4 sharp sand 1 cement and waterproof addative (is this the 1 shot rendermix, how much of this?) with 1 hydrated lime together.

Thanks for your patience.

Darren[/quote]

You can buy pva,render addmix ,sand cement etc from your local builders merchants.they usually deliver.
the pva you dilute with water and paint everything, if in doubt paint it.
the waterproof addmix comes with a plastic filler bottle attached to it,You really cant go wrong if you put too much in the mix.