Diagnose a Chimney Leak

gunadi · 06-28-2012, 07:35 AM

I have a leak in my attic that I think is coming from or around the chimney. I have posted some pictures below. The most obvious problem I see is that the caulk/sealant around the chimney flue has pulled away from the cap near the places you see rust. I plan to sand that rust away and reseal. Advice welcome.

I have also included pictures of the flashing (north side and east side). I don't see any problems but I don't have a lot of expertise. Does anyone see a problem?

Thanks much for any help.

Windows on Wash · 06-28-2012, 08:54 AM

Where the leak in the attic is should give you more direct feedback as the the origination of the leak.

The flue chase cover looks like it is flat and actually pitched in towards the flue.

I don't like the sloped roof coming into a chimney and especially behind siding where you can't see whats going on or what was done.

joecaption · 06-28-2012, 09:30 AM

Wrong roof boot, it should have had a flange that gets screwed down to the metal with metal roofing screws with silicone under the flange.
There also is no rain ring.

No cricket above the roof on the high side of the chimmney to devert water away from the chimmney.

Why is the J moulding cut where it meets the roof?

I run all the solid flashing and step flashing, then add a band of 1 X 4 vinyl lumber at the bottom of the chimney. On top of that I install Z moulding then install the J moulding and siding.
What this does is cover up and protect the areas most likly to leak.

Is this something someone added on after the house was built?

I've had to repair a few of these and 90% of the time it leaks because of the flashing done wrong in the corners and at the bottom of the chimmney.
I've removed the siding and a few shingles and could look right down inside the attic or at least at bare sheathing.

gunadi · 06-28-2012, 02:00 PM

Thanks for the response.

This is all original design and construction. The house was built 9 years ago. I am the second owner. I realize this is "out of warranty" but I called the builder anyway based on the comments here, and he responded that it is not his problem. He said the home inspector should have caught it if there was a problem. From what I hear here, this is not "wear and tear" but rather poor design.

AGWhitehouse · 06-28-2012, 02:48 PM

Poor design/construction indeed and from the builder's response it sounds like he knows it...

Follow WOW's advice and try to narrow the leak source down. That will help to determine exactly what remedy you'll NEED to do. Though I do recommend making plans to fix all the items Joecaption noted...

hotrod351 · 06-28-2012, 08:28 PM

must be flashed under that siding and thats hard to see. you could try runing water on the top and have some one inside look to see if water comes in but as for the siding well thats a whole different deal. you could also soak down around the base of the siding and roof and see if it comes in. it would be good for you if it didnt because you would have to pull that siding off to see whats going on under it.

AndyWRS · 06-28-2012, 08:30 PM

Here is what i would do to diagnose this leak:

Run the hose on the shingles above the chimney, do not wet the sides or top of the chimney.

If it leaks you know you have an issue where the roofing ties into the chimney.

Let it dry out....

run the hose on the chimney cap and check for leakage.

It is best to have someone in the attic, hopefully its not vaulted ceiling, and as you run water at each location you have a set of eyes watching in the attic.

It does look suspect, all of it.

CopperClad · 06-28-2012, 08:44 PM

Yeah... That is a hack job in its finest.. Hopefully you've caught it soon enough. Caulking will not fix that one. Call up Mike Holmes, he'll fix ya right up.

joecaption · 06-28-2012, 09:38 PM

Also those outside corners should not have been tite to the shingles. There's no way for then to drain if there to tight.

Windows on Wash · 06-29-2012, 08:17 AM

Quote:

Originally Posted by AndyWRS

It does look suspect, all of it.

I am going to copy this for future signatures. This about sums up most of the stuff we see on here in a nutshell.

gunadi · 06-29-2012, 11:18 AM

I am a newbie so forgive me but is there a diagram or picture that would illustrate the flashing design you recommend? I think I am missing something fundamental. The rain rolls down the roof hits the chase flashing and then diverts to... where? It seems to me that it is now under the shingles and on the roof decking. The cricket seems really, really important but even on the side flashing, how do you avoid water on the decking if the shingles run right up to the chase flashing. The J channel, if I understand, just diverts runoff running vertically down the siding.

Sorry if this is very basic.

Quote:

Originally Posted by joecaption

Wrong roof boot, it should have had a flange that gets screwed down to the metal with metal roofing screws with silicone under the flange.
There also is no rain ring.

No cricket above the roof on the high side of the chimmney to devert water away from the chimmney.

Why is the J moulding cut where it meets the roof?

I run all the solid flashing and step flashing, then add a band of 1 X 4 vinyl lumber at the bottom of the chimney. On top of that I install Z moulding then install the J moulding and siding.
What this does is cover up and protect the areas most likly to leak.

Is this something someone added on after the house was built?

I've had to repair a few of these and 90% of the time it leaks because of the flashing done wrong in the corners and at the bottom of the chimmney.
I've removed the siding and a few shingles and could look right down inside the attic or at least at bare sheathing.

AGWhitehouse · 06-29-2012, 12:21 PM

Step Flashing Detail: http://www.roofing.com/images/topics...1283305325.png

This picture shows a traditional brick chimney, but you should have the same basic flashing underneath your siding: http://nelliebryantroofing.com/image...y_flashing.jpg

**Gary in WA** · 06-30-2012, 01:10 AM

Just buy a zip tool and remove some bottom courses of siding, take more pictures- before the water test. 30" and wider chimneys require crickets; http://publicecodes.citation.com/ico...003_par034.htm

Your storm collar is cemented to the cap material, should be up an inch or so and not cemented. The cap should have a raised 1" lip integral to it- the pipe passes through. The collar can be caulked to the pipe, not both as the expand/contract differently. (You want the seal at pipe/collar to direct water out away from pipe onto collar).

It appears you have at least one fastener in the cap flashing, make sure each corner has one, not to blow off in a pressure difference high wind.The diagonal folds are still present in the metal, it doesn't appear distorted to pond water; http://inspectapedia.com/chimneys/Wo...mney_Chase.htm

Gary

Tom Struble · 06-30-2012, 08:10 AM

Gary got it right,you need to pull some siding,probably will be something simple like no paper over the step or corner flashing not proper or a piece of step slide down

you can get a zip tool,but thats Monogram and it will fight being unlocked a bit

Rockford · 07-17-2012, 04:46 PM

Gunadi,
The Chase Cover on the top is definitely causing some of the problems. The cover is sagging and collecting water and snow (depending on where you live). Once the seal cracks around the storm collar (where the rust is beginning to show) and also above where the storm collar appears to be broken. There is nothing to prevent the water from going down through the chase and into your attic. The chase cover should have a minimum of a 2" high collar around the pipe to prevent water intrusion, along with a tight fitting storm collar. The chase should be made from a material that resits corrosion to prevent rusting and holes.