Gable End

[jrterror0]

Hi,
I have a gable end to rebuild and I am considering using blocks instead of the existing bricks. It is only a small section of wall, single skin I believe, 8' long with it's highest point being at the centre and this is 4' high. (A triangle). I intend on placing a window in this expanse, this measures 3' by 1'. I was wondering which type of block I should be using. The gable end may be exposed to a lot of weather and because it is single skin shall be plastered on the interior, so it needs to keep the damp out, however ideally I do not want to render the exterior. Also, should I be using different types of blocks at each side of the window to support the lintel that shall in turn support the blockwork above the window? High density blocks perhaps? Which type of block has the best water resistance?
What do you advise?

 

[r896neo]

frankly a single 4'' skin is not suitable for a wall that needs to keep water out and a 4'' block wall has no chance if its not rendered/ roughcast. You will not get a waterproof result with any kind of unprotected block unless you are prepared to spend lots of money on waterproof treatments/ tanking.

I assume this is for a garage/ outbuilding? If you don't want to render it can you perhaps clad it with something?

 

[jrterror]

Hi.
No its on the house, but out of sight. Like I said it sis only a small area. I am assuming that it is single skin. Are there no blocks that are water repellant then?

 

[noseall]

All masonry products are vulnerable to wind driven rain. More importantly, a single skin wall (100mm thick) is equally vulnerable to the cold and condensation problems attributed to it.

7n dense concrete blocks will be fine for the task but will only perform as a single skin structure.

If you are looking to keep the interior dry and condensation free, then you may need to add battening and insulation to the inner face.

Otherwise render the outside.

I would be inclined to fix restraint straps also, though this could be prohibitive with just a single skin gable.

 

[^woody^]

Hi.
Are there no blocks that are water repellant then?

Lego blocks maybe, but concrete ones are not water resistant at all - and neither will the mortar be

Putting a window in this small an area may also cause some stability issues

 

[r896neo]

you may need to confirm the construction type as unless it is a timber frame house with a brick skin it is pretty unlikely to be a single skin construction.

 

[jrterror]

Great help. Thank you
Can some one explain the following...
7n dense concrete blocks will be fine for the task but will only perform as a single skin structure.

 

[noseall]

Great help. Thank you
Can some one explain the following...
7n dense concrete blocks will be fine for the task but will only perform as a single skin structure.

It means that the wall interior will be vulnerable to all the damp problems associated with single leaf walls, i.e. condensation and penetrating damp etc.