A ? about roof flashing

**journeyman Mick** · 19th February 2007, 04:09 PM

Okay, got this from the Australian Domestic Construction Manual, which was written by Standards Australia and Master Builders Construction and Housing Association Australia Inc, in conjunction with major manufacturers of building materials, the Timber Research and Development Advisory Council and several statutory bodies.

Text accompanying the stepped flashing diagrams:
"Cavity gutter detail
A critical area of cavity flashings occurs where exterior brickwork becomes internal below a sloping roof. Proper stepped damp-proof course from brickwork on to the adjacent roof level must be provided in conjunction with a cavity gutter, or alternatively a stepped flashing (laid across the cavity) can be used. One way of creating such a gutter is shown in Figure D7.2 - G."

My emphasis and italics. Note that there's no proviso for not providing such a flashing with associated cavity gutter or stepped flashing for renovations or additions. Manufacturers may give other methods for retrofitting a flashing in such a case, but when the wall leaks and the client sues you you'll need to sue the manufacturer that gave you the advice.

The manufacturer will most likely have deeper pockets than you.

If it's not in the ADCM or the BCA then you use the method at your own risk. Follow all the rules and you and your license are covered. If you cut 60% of the way into a brick wall and sometime down the track it collapses, killing or maiming someone then you'll be getting sued. It will then be up to you to countersue the engineer or manufacturer who gave you that advice. I've even read advice in the Master Builder's magazine that in such cases your estate could even be sued by the injured parties after your death.

The diagram labelled DPC shows the DPC running from under the bottom plate and down the step in the slab to finish under the lower course of bricks.

"Damp proof coursing must be installed as follows-
The full width of the wall
If near ground level, between 150mm and 200mm from the finished ground level."

If the DPC must be installed the full width of the wall it must be installed under the bottom plate as that is part of the wall. If stepping down one brick from the bottom plate sees the DPC being closer than 150mm from finished ground level then the builder has not had the slab formed high enough.

WRT to the brick ties:
"The following precautions should be taken during construction:
...............Bridging may occur at the bottom of the cavity, brick ties and at window flashing..........."

Nowhere is it specified that ties should be fixed at an angle in order to shed water and prevent bridging, but if it was my job I'd be making sure they were, as I wouldn't want any warranty call backs to fix damp spots in plasterboard.

Mick

**ozwinner** · 19th February 2007, 04:26 PM

No one does it like that either Mick.

Ill try to draw something up, or maybe I can get it from the Brickwork Standards I have here.

This is fun.

Al

Edit: The brickwork standards dont have any pics of flashing, you have to buy the flashing standards..

**Bleedin Thumb** · 19th February 2007, 05:20 PM

The drama, the suspense ....its killing me!

This thread has more twists and turns than a John Grisham novel!

BTW Bricks if you are going to post links that are relevant to any point, could you link to the appropriate page so everyone doesn't have to wade through a tech manual.

I skimmed through every one of those links (except 2 that wouldn't open and I can't see the relevance to your argument. I may have missed it but do you expect people to read 600 pages to prove your point?

**Groggy** · 19th February 2007, 05:44 PM

This works for me. If you need more detail then download it from here.

**ozwinner** · 19th February 2007, 05:59 PM

Greg the pics too small and it doesnt include all the flashings.

Al

**Groggy** · 19th February 2007, 06:02 PM

Originally Posted by ozwinner

Greg the pics too small and it doesnt include all the flashings.

Al

did you try clicking on here <- to download it? If it seems small after downloading, click on it, that should zoom in (on IE anyway). If there is a particular flashing you want shown, let me know and I;ll see if I have it in the book.

**ozwinner** · 19th February 2007, 06:21 PM

Ok so I clicked HERE this time, the pic was bigger, but there is a few flashings missing.

Missing.

The flashing that seals off a roof from the adjoining brickwork.
This is the one that Bricks was one about, I think.

I think the boys were on about different flashings myself and got all heated up about different things, both were right in their own respect.

The cavity flashing above a room or void is missing.
This is the one that Pawnhead was one about, I think.

One flashing on the picture that isnt used anymore is the sill flashing.

Unless it rains, all flashings are redundant anyway..

Al

**Groggy** · 19th February 2007, 06:25 PM

How about this? Click here for the big picture.

**ozwinner** · 19th February 2007, 06:54 PM

Ok so you now have the roof to building flashing.

What about the cavity flashing over openings.

Hijacked by mods, whod a thunk it?

Al

**Groggy** · 19th February 2007, 07:21 PM

Originally Posted by ozwinner

What about the cavity flashing over openings.

I reckon you're just after a complete copy of the book Al

.

Windows (no doors): click here for the large size.

**ozwinner** · 19th February 2007, 07:31 PM

Originally Posted by Groggy

I reckon you're just after a complete copy of the book Al

.

Windows (no doors): click here for the large size.

Dont worry, I have the book in my head anyway.

This is what I think Pawnhead was on about, cavity flashing.

PS, whats the book?

Al

**Groggy** · 19th February 2007, 07:37 PM

Originally Posted by ozwinner

PS, whats the book?

Bricklaying for Dummies

Staines, Allen. House Building Manual: Step by step Guide to House Building 4th Ed. ISBN 1-875217-18-5 purchased from Bunnings

**ozwinner** · 19th February 2007, 07:41 PM

Originally Posted by Groggy

Bricklaying for Dummies

Staines, Allen. House Building Manual: Step by Step Guide to House Building 4th Ed. ISBN 1-875217-18-5 purchased from Bunnings

Ive got the decks and pergolas book..

Im going to call mine Uncle Al's Bricklaying guide. (Im not really

)

Maybe something Bricklaying.....

Al

**ausdesign** · 19th February 2007, 08:32 PM

An abutment flashing !!.

**ozwinner** · 19th February 2007, 08:51 PM

Originally Posted by ausdesign

An abutment flashing !!.

Sounds painful..

I hope you get over it soon..

Al

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