efflourescence

newhouse

has anybody experienced efflourescence on their roof from brick chimneys and if so how did you remove it/stop it?

Dupont

if its from your brick chimney clean it off with a stiff/wire brush but dont use water. but i dont think it would drop onto a roff it is more likely the lead work around the chimney that produces a white run off if not treated with patanation oil

newhouse

Dupont wrote: »

if its from your brick chimney clean it off with a stiff/wire brush but dont use water. but i dont think it would drop onto a roff it is more likely the lead work around the chimney that produces a white run off if not treated with patanation oil

thanks for this Dupont

PaleRider

You must be in the east of the country. If the chimney is new it may be ok over time. Depending on brick type / Quailty, salts can be present in the bricks, and also the mortor. But usally it's fine. The white powder will disappears over time.

If for example the bricks bricks get to wet before being built not good etc etc.

newhouse

PaleRider wrote: »

You must be in the east of the country. If the chimney is new it may be ok over time. Depending on brick type / Quailty, salts can be present in the bricks, and also the mortor. But usally it's fine. The white powder will disappears over time.

If for example the bricks bricks get to wet before being built not good etc etc.

thanks for this Palerider (living in Kerry)
we thought we did everything right - the bricks are new, we kept them dry, used lime in the mortar, oiled the lead (twice), the chimneys were built in fine weather..(3 months ago)
the bricks are getting drenched through...now we think that the cap might not be good enough and so will replace them when the weather improves
any opinion on products to remove the stains from slate? the white is remaining even after numerous brushings

PaleRider

The reason I thought you lived in the east was because Brick chimney's don't do well on the west coast, they get to much driving rain. Plastered chimney would be best. The sand infill can get wet and introduce damp. This may be the problem, that's the reason we in the west build & plaster.

The cap may not be leaking, the rain in driving through the brick. Not a good idea to depend on brick chimney in the west.

You could plaster the chimney if all else fails. Let me know how you get on.

Building reg may not allow; brick chimneys in the west.

newhouse

PaleRider wrote: »

The reason I thought you lived in the east was because Brick chimney's don't do well on the west coast, they get to much driving rain. Plastered chimney would be best. The sand infill can get wet and introduce damp. This may be the problem, that's the reason we in the west build & plaster.

The cap may not be leaking, the rain in driving through the brick. Not a good idea to depend on brick chimney in the west.

You could plaster the chimney if all else fails. Let me know how you get on.

Building reg may not allow; brick chimneys in the west.

thanks for this, we are rebuilding the chimney caps today - hoping it makes a difference!

Poor Uncle Tom

PaleRider wrote: »

Building reg may not allow; brick chimneys in the west.

Please explain this comment.

PaleRider

Poor Uncle Tom, when i mentioned the Building Reg's, I checked up and I refer to Homebond up dated Edition 2001 page 117 Quote; "The Chimney that will give least trouble from rain penetration point of view is the rendered stack with precast concrete chimney capping, properly haunched and sealed at its junction with the flue pipe"

Also if you take a look at map on homebond it gives examples of exposed areas, the whole west of country is classed as Severe; 5m2/sec/yr. Therefore not a great location for Brick Chimney's, however I suppose not impossible.

I believe that Brick chimneys are best avoided in the West Coast; if possible.

The exposed parts of buildings, such as chimney stacks, are particularly vulnerable to the effects of severe weathering and structural failure.
You could say that Homebond are flagging problems with the unrendered chimney.

I suppose that a chimney properly built with regard to location will preform satisfactory.

A GUIDE TO THE REPAIR OF HISTORIC BRICKWORK
Different brick types will vary in their ability to withstand frost damage. Porous bricks will absorb more water and some may have poorer frost resistance than denser bricks. It should be noted, however, that there is
no dependable correlation between strength or water absorption and frost resistance. Frost resistance relates to the pore structure of the brick.

Erosion of both bricks and mortar joints by the action of wind, rain (and accompanying frost and sulphate attack) can seriously weaken a chimney stack.

OP if you could post some photos.

Poor Uncle Tom

Yes, what you describe is 'good building practice' and the Homebond Manual is a good reference guide.

But, the Homebond manual is not the Building Regulations and it is not a good idea to tell people that if they are in the west of the country and have a brick chimney they could be in breach of the Building Regulations.

PaleRider

Poor Uncle Tom wrote: »

Yes, what you describe is 'good building practice' and the Homebond Manual is a good reference guide.



But, the Homebond manual is not the Building Regulations I did not say anywhere in my post that homebond was the Building Reg's

and it is not a good idea to tell people that if they are in the west of the country and have a brick chimney they could be in breach of the Building Regulations.

Poor Uncle Tom

I did not say anywhere in my post that homebond was the Building Reg's

Nowhere did I say for people not to build Brick chimneys in the west.


When I referred you to homebond I thought you would have understood that where my reference was coming from. I knew Homebond is not the Reg's

Hence; Building reg may not allow; brick chimneys in the west.

Maybe there is a submission that could be made to the department re; chimneys.

Poor Uncle Tom

In the interest of clarity:

The construction of a brick chimney is not prohibited in the west of the country under the Building Regulations.

PaleRider wrote: »

Hence; Building reg may not allow; brick chimneys in the west..

This statement is misleading.

PaleRider

Tom
In the interest of clarity:

I do understand

The construction of a brick chimney is not prohibited in the west of the country under the Building Regulations.

However. that is why used the word may.

OP I would be interested in knowing things are going for you.

newhouse

palerider
i did not misinterpret your reply - thanks for your advice - have changed the cap style on one of the chimneys on saturday, it still has a wooden surround - waiting for it to set - will let you know how it goes, though it'll probably be a few weeks..and will post photo soon
(also we put a good complete lead tray in on day one where the blocks stop and the bricks start so it's obviously doing it's job - i.e. rainwater and efflorescence coming out at base of chimney where tray is positioned and not going down into the house!)

PaleRider

newhouse;

That will be fine, hope it's works. Lets us know how things go.

Thanks