Will the combustion exhaust from my condensing gas boiler harm my home's brick outer wall?

stuckinthedirt

I had a Buderus condensing gas boiler installed several years ago. The installer explained that a PVC flue is used for the combustion exhaust because it is acidic. If I were to send the exhaust up my terracotta flue, the acid would eventually cause the flue to degrade and collapse.



Well, that has got me thinking about the outside of my home where the exhaust comes out. I have a brick home, and the exhaust comes out right up against the side of the house. I am sure that some of the moisture in the exhaust ends up on my brick. So I am wondering if I should be concerned about the long term impact on the brick. Would the acid from the exhaust gas begin to degrade my brick? (Similarly, the condensate is pumped out onto the ground right outside my house - how may that impact my cinder block foundation.) Has anyone looked into this? Is there any need for concern? If so, what would be a good remedy?



Thanks, Ed

Jamie Hall

If the exhaust does come out

so close to the house that it can -- at least on occasion -- condense on it, yes it will damage the brick wall.  Not, actually, the brick, but the mortar.  However, if it gets even a little diluted by air, it won't -- so the obvious solution is to extend the exhaust enough so that it is discharging some little distance -- even a few inches -- from the wall.



The cinder block itself may be degraded by the condensate, but it should be a slow process.  None the less, it might be wisest to arrange things so that it can't drip on the block.

John Mills_5

out

The exhaust should blow straight out from the house, not elbow and blow along the house where it will damage the mortar and possibly stain the brick. 

mastercraft

No

It should blow straight out & wil immediately mix w' ambient air.  I'd be very surprised to see it stain or 'eat' the brick.  I'd be more concerned at emitting  condensate outside.  Water acts funny when it hits 32 degrees....... 

stuckinthedirt

Thanks

Thanks all for your input. The exhaust currently is pointed along the side of the house. Once it warms up a bit, I will go out an change it.

hot_rod

put some litmus paper

on the brick wall It will show you the ph of the vapor hitting the wall.



I have seen condensate cut a groove in a concrete floor over a years time. Fairly simple to add a condensate neutralizer to the line, and sleep better.



Build your own neutralizer with some PVC fittings and some limestone or marble chips from a gravel yard or pet store. Search the Wall and see some clever DIY designs.