Spalled Brickwork- Is render appropriate?

[Stevefightsbears]

Hi all,

Some advice would be highly appreciated.

I have some spalled brickwork on the gable end of my house and there is some penetrative damp coming through in these areas. (Roof and guttering newly replaced so 100% sure it is the brickwork). I have since DPM'd internally and replaced blown plaster but want to tackle the problem at its core.

I have had some tradesmen come out and say that the best thing to do is to just render it with HB12 base coat with mesh and then apply one coat render. All breathable apparently.

My question is, will this work or just hide the problem? Do the spalled bricks need to be replaced or would putting a render coat over the top be the best solution and make the wall waterproof?

Thanks in advance.

 

[tell80]

Steve Hi,

Why not post pics of the whole gable, & detailed close ups of the worst area of spalled bricks?
And pics of where you have done some remedial work - or any other water damaged areas?
What do you mean by "DPM'd internally" - have you had some kind of wall tanking installed?

 

[^woody^]

My question is, will this work or just hide the problem?

It depends what the problem is.

Suitably specified render will protect a wall. Damaged bricks will need to be replaced or otherwise the face rectified to prevent further delamination once the coating is applied.

However the cause of the spalling may be something other than or in addition to frost, so that needs to be determined first before a solution is devised.

BTW, we don't need pictures of spalled bricks.

 

[Deleted member 292770]

thing to do is to just render it with HB12 base coat with mesh and then apply one coat render.

Sounds like a plan, but may need k priming and possibly pinning the mesh to the wall.
Your plasterer will know.

 

[Stevefightsbears]

@tell80 yes tanking internally, but obviously not tackling problem at cause.

Thanks for reply @^woody^, I'm fairly certain it is just frost damage that has happened over 30yrs and not been addressed. The area is shadowed by another house and I think the freeze/thaw that has occurred over the years has caused the delamination. So- do you think the spalled brickwork needs to be removed & replaced prior to rendering or it'll be protected by the render?

I should add there are very similar properties on the road that have rendered and it seems to have resolved the issues.

 

[Stevefightsbears]

Here's some pics-

To replace or to render over? or both

 

[^woody^]

You may want to consider applying a facade cream/water repellent as an alternative to render. These can protect against frost damage.

 

[tell80]

Steve,
Thanks for the pics, they are always useful. Internal pics would also help
to show what kind of damp damage you have, and where on what floors?

You have a cavity wall so in theory you shouldn't get penetrating damp.
However, there are a number of ways for cavities to be bridged.
I presume you have had the tanking work done on the ground floor?
The gable has been re-pointed in the past - not very successfully.

 

[Stevefightsbears]

@tell80 The wall is solid- not cavity. The damp was on the first floor- it has now been rectified with a damp proof membrane and plastering so nothing to show. I certain it is the the 'sponge' like quality of the delaminated brick surface. Should I remove and replace said bricks (at a substantially higher cost I imagine) or just render over?

 

[stuart45]

The gable has been re-pointed in the past - not very successfully.

Looks like it might have been done with a strong sand/cement mix which could help the spalling.

 

[tell80]

OP,
Good call, I was wrong but what is the lower pic? Is there an extension/outrigger butting up to the gable wall.
Tanking upper floors is unusual.
Given the neighbour's successful experiences with rendering, & the fact that you've got a solid wall, then I would go for render.

 

[Stevefightsbears]

@tell80 I think its just a drain pipe! . The tanking/dpm was necessary as at the time the wall was too wet to dot and dab onto.

Thank you all for your help all- I'll go with the render. Fingers crossed I don't have to rip it all down a year later, lol!

 

[stuart45]

Looks like a cavity wall tell80 as it's all stretchers, but I have worked on a property that was a solid wall built in stretcher bond.
Some surveyors call it a finger cavity, but it can have damp issues due to a hollow wall joint.

 

[Bonni]

Render should be banned, one sure way to trap moisture in bricks and blow them. If anyone thinks render seals a brick wall, they sadly don't have a clue.

 

[tell80]

Bonni,
All render, or just certain renders should be banned?
What does "seals" in your "seals a brick wall" mean?

The problem would be that basic sand & lime renders over brick have successfully been around for at least 2500 years, & some of the most beautiful, few hundred years old buildings in the UK were also rendered over brick.

Thing is, its sometimes a case of render or no render as in a rock and a hard place.