Chiminy "dripping" after heavy rain

[ROSEY]

Thought that I would try to get some advice.........My 5yr old brick chiminy tends to leak (drip) rain water past the flue into the firebox only during a heavy rain such as today (Earnesto). I suspect that it may be coming thru the top parging since there appears to be some hairline cracks in the cement. What do you think/recommend ???...is there a "rubberized" type coating that I can seal it with?? What about the rest of the chiminy.......what's the best way to waterproof the brick???..I do have "rain caps" installed...thanks

[egon]

What type of liner and raincap do you have?

Egon

[Pat]

If there is a goodly wind with the rain even a new well sealed chimey might leak from water blowing into the cap. I built one that was a rectangular solid with its flat "roof" considerably larger in extent both NS and EW than the hole in the chimney. Used relatively fine mesh expanded metal for the walls. It breathed just fine, kept glowing embers in for the times when I got too carried away making fire, and let very little water in. Of course that was in San Diego with about 13 inch annual rainfall. Still we did get HEAVY rains once in a while althoughusually without really heavy winds.

It could be aerodynamics. There may be a direction from which a strong wind causes an eddy or whatever that develops a high pressure area at the top of your chimney. In that case just about any chimney would leak.

If you want to try sealing around the chimney there are caulks designed for high temps (they contain some fine silica sand I think) which will not be harmed by any temps you would likely experience. These caulks will take high temps that you would encounter where the exhaust stack of an insert exits the fire box and other hot spots. If the area you want to seal doesn't get all that hot you could use a good sililcone rubber worked down into the cracks. Don't use the cheap stuff, go for the 50 yr type GE or better.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[ROSEY]

The chiminy was constructed with those orange "fired clay" liners and I installed "clamp on" rain caps sold at LOWES.

[egon]

As per Pat, the wind and turbulence may be allowing some rain into the chimney cap openings.

Does it leak with a normal rain and light wind?

Sorry about all the questions and no answeres. [img]/forums/images/icons/confused.gif[/img]

Egon

[ROSEY]

Egon.....thanks....NO DRIPS after normal rain with no wind.

[egon]

Rosey:

All I can say is check out the cap area and try and determine what the circumstances are for the drips. Perhaps a different design cap ??? If you do some sealing Pat's given better advice than I can.

You mentioned sealing the bricks. There are probably different opinions on this but my own feeling probably influenced by some reading is not to seal. If water does get behind the bricks it cannot permeate through the brick to atmosphere and will result in spaling of the brick when heated. Pro's and con's on this subject and I am not too conversant with it.

We have a chimney built exactly as yours is that has many spalled bricks on it. From what I can tell it was sealed prior to our purchase of the house.

Now I'll have to find the ambition to make up a coloured mortar mix and climb the ladder to effect some repairs. It's a new ladder just for this job. The materials have all been assembled a few times but still no repairs! [img]/forums/images/icons/confused.gif[/img] [img]/forums/images/icons/confused.gif[/img]

Egon [img]/forums/images/icons/grin.gif[/img]

[ROSEY]

Egon....appreciate the feedback. I ordered a product called "crown-seal" which is an elastised "trowel on" product made specifically to seal hairline cracks on the top crown of a chiminy. I do have hairline cracks there which I suspect may be the source of my problem. Also am going to apply a masonary sealer made by BEHR which is "Breatheable" in that it allows moisture to exit the surface not enter it...to the rest of the exterior brick. Hopefully this will solve my problem. Thanks again,,,Rosey

[Pat]

Rosey, The sealer that stops liquid but passes vapor is a great idea but if a long duration rain with little or no wind doesn't give you any water in the chimney then the likely source is aerodynamic and not surface cracks. You will know after you seal everything nice and proper like and you get a strong rain with wind. I'm betting you will get drips. Hoping you don't but thinking you will.

[img]/forums/images/icons/smile.gif[/img] [img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img] [img]/forums/images/icons/smile.gif[/img]

[ROSEY]

Thanks Pat...........hope you are wrong since I have gas logs and they are not condusive to water dripping on them [img]/forums/images/icons/tongue.gif[/img] ...anyway we shall see ..........