Flashing junctions between papaper wall coping tiles and vertical masonry surfaces

[Michael Thomas]

Assuming that there is no flashing under the tile to extend up the wall and counter flash, does anyone have a link to an effective flashing design for the junction of parapet wall coping tiles with adjacent vertical masonry such as these two chimneys?

Thanks

[Mike Moser]

Try Asphalt shingles | NRCA National Roofing Contractors Association (http://www.nrca.net/consumer/types/asphalt.aspx#flashings)

scroll all the way down and you will see some details

[Michael Thomas]

If we are looking at the same diagrams, these details are appropriate for a sidewall flashing to an appropriately sloped roof where the shingles provide the primary water barrier, they do not work where the problem is a watertight interface with horizontal top of a curved coping tile.

The problem is not that I don't know how such a flashing should be constructed, the problem is that I need a third party industry source I can reference when describing it. (This is for the water intrusion, not the HI, side of my business).

[Mike Moser]

The top tile should be watertigh by itself. The sidewall block can have a reglet cut into it so the wall is watertight. The termination detail can be used all the way up to a point directlyunder the tile coping. The only other alternative is to remove the tile and run membrane and or flashing over the top and reinstall the tile. This is rarely done.

[Markus Keller]

I looked through every diagram in my 2010 NRCA manual. Couldn't find anything diagram or reference specific to that application.
On the new CMU pic, a standard counterflashing should work. I can send you a couple diagrams from the manual.
On the vintage pic, I wouldn't worry about a flashing at all. Get rid of the mortar and replace with a sealant. Various caulks will work. One of the standard ones I see on jobsites is Dow 790, Sika or Solarseal. If sealed properly once, I don't see that as a big water point.

[Michael Thomas]

The only other alternative is to remove the tile and run membrane and or flashing over the top and reinstall the tile. This is rarely done.

Yup... though every manufacturer of virtuous clay coping tile I contacted requires that flashing.

[Michael Thomas]

I looked through every diagram in my 2010 NRCA manual. Couldn't find anything diagram or reference specific to that application.
On the new CMU pic, a standard counterflashing should work. I can send you a couple diagrams from the manual.
On the vintage pic, I wouldn't worry about a flashing at all. Get rid of the mortar and replace with a sealant. Various caulks will work. One of the standard ones I see on jobsites is Dow 790, Sika or Solarseal. If sealed properly once, I don't see that as a big water point.

Can't find it anywhere either - this is a liability control issue for me, I don't like to recommend anything that cannot be referenced back to an industry standard.

Complete agreement that a properly speced and applied elastomeric sealant is miles ahead of mortar in that location.

[Jerry Peck]

Michael,

They've got some decent coping and coping flashing details here.
- PAC-TITE Coping | PAC-CLAD Metal Roofing (http://www.pac-clad.com/metal-perimeter-systems/pac-tite-coping/)

Personally, I would have expected a bit more detail and a flashing/counter flashing at the side wings of the coping endwall than what they show.
- http://www.pac-clad.com/wordpress/wp-content/themes/pac201102/e-tools/file-request.php?did=1043
- http://www.pac-clad.com/wordpress/wp-content/themes/pac201102/e-tools/file-request.php?did=1044

[H.G. Watson, Sr.]

Look at details for wall expansion joints and raised expansion joints

[PeterPan88]

Thought I would share this Masonry, Tuckpointing, Bricklayer Renovation Chicago, IL - Walter's Masonry (http://www.waltersm.com/). The most professional masonry company in Chicago. If you or your friends and relatives need a reliable masonry check out their website. They even offer a free estimate!

[ROBERT YOUNG]

Yup... though every manufacturer of virtuous clay coping tile I contacted requires that flashing.

From what I was taught, a coping stone or metal coping is all that is required.

On a parapet, the top outer & inner course of the wall assembly would have a dimensional wood, lets say 1 x's what even the width.
Flashing in the inside vertical assembly and coping lateral fashioned atop the coping board. The sides are usually 4" over both sides.
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Stone coping requires no flashing material on the wall assembly. Flashing are berried in the mortar32233

[Michael Thomas]

I inspect a building or two a month with severe damage to the rook decking and/or truss ends due to missing or incorrect through-wall flashings under parapet cap stones.

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[Jerry Peck]

If the coping stone was continuous with no joints anywhere - moisture would still penetrate through the stone and into the wall below.

Add discontinuous stones and associated joints and the moisture penetration will be greater and quicker.

Make the wall grouted solid and the moisture storage capacity increases, reducing the moisture penetration amount and speed.

The parapet wall is required to have a coping flashing, either on top of everything or on top of the wall and under the stone.

Make the wall a cavity wall and ... you've got a real mess just waiting to happen.

[ROBERT YOUNG]

If the coping stone was continuous with no joints anywhere - moisture would still penetrate through the stone and into the wall below.

Add discontinuous stones and associated joints and the moisture penetration will be greater and quicker.

Make the wall grouted solid and the moisture storage capacity increases, reducing the moisture penetration amount and speed.

The parapet wall is required to have a coping flashing, either on top of everything or on top of the wall and under the stone.

Make the wall a cavity wall and ... you've got a real mess just waiting to happen.

I am going back, and have opened up many a residential wall that lasted decades without a membrane and just the flashing and copping preventing water intrusion.
Today, membrane flashed over the parapet and lapped at the striping if it is a BUR system seems to be how the installers do it today.

[Michael Thomas]

I don't do HI any more, all I do is consulting work at leaking properties, so ALL I see on a day to day basis are the buildings where there are construction defects causing water intrusion problems.

Unfortunately, here in Chicago, that's almost every multi-story masonry building less than four or five stories built since 1990 - 90% or more of such construction has at least some problems related to such defects, and the majority of serious damage I observe is caused by water entry at parapet walls.

In my experience a traditional structural brick wall is a totally different beast than the veneer over block cavity walls (and even single wythe block-walls) I see regularly here in Chicago - older solid masonry walls do deteriorate absent cap flashings, but much more slowly.

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As for clay tile copings: absent flashings below the tiles here in Chicago, at new construction with CMU single wythe parapet walls significant cracking often starts after the first winter.

At most older structural brick buildings there is at least some deterioration, and in Chicago neighborhoods with older buildings with such construction every third or fourth building will have its walls completely re-built above roof level.

Often, when tiles coping have been replaced with new tile and no flashing, new damage to the walls below will be apparent within a few years.

[ROBERT YOUNG]

Michael I am happy you are consulting and not inspecting homes any longer.
I would feel proud of the accomplishments you have made, truly!

Sounds like there is a lot of work in Chicago for you in the foreseeable future.
If you run into Condo Bob Elliot during your travels say hello to him from the Northern homie:-) He is a fine man and great home inspection representative.

You statement; "In my experience a traditional structural brick wall is a totally different beast than the veneer over block cavity walls (and even single wythe block-walls)" is spot on.

I did not express myself as you have so eloquently.
Thanks for putting a conclusion to my sometimes poorly exampled posts as compared to you gentleman.

I will continue to strive and learn to be a better inspector, and hopefully one day do some consulting work as you do. I am happy I am always eager to have something to look forward to. Makes life a challenge and fun!

Best regards.