Weep Vents

[Shytalkz]

A quick search of NHBC Standards contains, inter alia, these references to moisture penetration:

(e)cavity trays
The single brick thick external leaf of a cavity wall can allow moisture into the cavity.Cavity trays should be used so that water drains outwards above openings.

Where fairfaced masonry is supported by lintels:

weep holes should be provided spaced at maximum 450mm intervals. Each opening should have at least two weep holes.
cavity trays or combined lintels should have stop ends.

(b)rain penetration
Rainwater will penetrate the outer leaf of a masonry wall in prolonged periods of driving rain. Resistance to rain penetration of masonry walls can be improved by cladding the wall. Total resistance can only be achieved with an impervious cladding.

Want me to find some more for you?

 

[joe-90]

You go on believing in the massive failure rates of roofing felt at eaves level, even though roofs originally did not have roofing felt and that via the wallplate is the only way that moisture can enter the cavity, if it pleases you. (He will ).

I look forward to hearing about your next project with a cavity wall where you refused to put cavity trays in, or weepholes and yet still obtained a completion certificate, how you single-handedly caused the entire BRegs and NHBC Standards to be rewritten as a result and even authored a new BSCP all on your lonesome, following which you were feted by all the captains of industry and obtained a knighthood for services to the construction industry.

So you are saying that you have never seen a leaky roof in the vicinity of a cavity wall? Then you are no Structural Engineer. Are you saying that you have never seen badly fitted windows whereby the wind pressure blows rain past them? Then you are no structural engineer.
I know what the regs say but I know it is a belt and braces measure. A similarity could be drawn with a water tank overflow (often called a warning pipe). It does nothing until there is a problem. Weep vents are the same. Have you ever seen a weep vent 'weeping' unless there was a serious underlying fault that needed remedial action? We lived in single leaf homes for millennia without water ingress into our homes.
The only reason that cavity walls came in was to break thermal conduction between inside and outside. Why do I have to educate you?

 

[joe-90]

A quick search of NHBC Standards contains, inter alia, these references to moisture penetration:

(e)cavity trays
The single brick thick external leaf of a cavity wall can allow moisture into the cavity.Cavity trays should be used so that water drains outwards above openings.

Where fairfaced masonry is supported by lintels:

weep holes should be provided spaced at maximum 450mm intervals. Each opening should have at least two weep holes.
cavity trays or combined lintels should have stop ends.

(b)rain penetration
Rainwater will penetrate the outer leaf of a masonry wall in prolonged periods of driving rain. Resistance to rain penetration of masonry walls can be improved by cladding the wall. Total resistance can only be achieved with an impervious cladding.

Want me to find some more for you?

Let's stick with science and experience shall we? That was probably written by a well-paid engineer that has never seen a wet house.

Answer the questions I've set you.

 

[staningrimsby]

Guys i thought i was asking a straight forward question and thought i might have got a simple reply, instead it seems to be a battle of the super powers.

The new extension will be rendered within a month or two of it going up if that makes any differnece to the need of cavity trays and weep vents.

 

[Shytalkz]

So you are saying that you have never seen a leaky roof in the vicinity of a cavity wall? Then you are no Structural Engineer. Are you saying that you have never seen badly fitted windows whereby the wind pressure blows rain past them? Then you are no structural engineer.

As ever, you twist (or completely ignore) words to fit your argument. I never said never, I said, as did others, that water penetration via wallplate level is not the sole reason for moisture penetration.

I know what the regs say but I know it is a belt and braces measure.

Again, where did I disagree with this statement?

Why do I have to educate you?

You don't. And more to the point, you can't: there is nothing about construction issues that you can pass on with any degree of authority.

 

[Shytalkz]

Guys i thought i was asking a straight forward question and thought i might have got a simple reply, instead it seems to be a battle of the super powers.

Whenever Joe gets involved, what would you expect? Tea, biscuits and complete agreement?

The new extension will be rendered within a month or two of it going up if that makes any differnece to the need of cavity trays and weep vents.

You'll still have to put them in, BRegs says so.

 

[joe-90]

Thank you for your ungracious climb-down. Now let your ego drop. I've learned much from listening to the least educated brickies, plasterers etc. You can too.

Bet you can't find a hard hat to fit you.

 

[staningrimsby]

Boys, boys, boys, boys, boys,

Ive got 5 kids and they don't arguee this much.

 

[Shytalkz]

If Joe was one of your progeny, believe me, they would .

 

[Shytalkz]

Let's stick with science and experience shall we?

We can't, as you have neither the qualifications nor experience to comment with any authority. I seen it wiv my own two eyes, twas wet and dark at wallplate level, this is the reason, master is not a scientific approach.

That was probably written by a well-paid engineer that has never seen a wet house.

Yes, that's right, conveniently ignore that you have been shot down in flames. Again.

Answer the questions I've set you.

I did.

 

[joe-90]

Didn't they ever teach you at school that science IS observation.

You are on the ropes, matey-boy and we can all see it.

 

[joe-90]

If Joe was one of your progeny, believe me, they would .

Tells me much about your parenting skills.

 

[Shytalkz]

Didn't they ever teach you at school that science IS observation.

That's as maybe, but one swallow and all that.

You are on the ropes, matey-boy and we can all see it.

If I'm on the ropes, then you clearly are deluded - but then we all knew that.

 

[Shytalkz]

Tells me much about your parenting skills.

Yes, you're right, how could I ever have thought that you were created in the normal way, rather than from surprising biological interaction of a rancid piece of offal and DNA scrapings from a filthy, bug-ridden carpet.

 

[gangman]

I would like to add my views on this, and these are based on observation and personal experience.

I have seen water ingress at plate level, through an outlet in a parapet wall. It was bad workmanship in that the hopper was to high and when the pipe blocked, the hopper filled and water run into the cavity on ply under the lead outlet. This is a one off on a flat roof, on a pitched roof there would be no consideration given to water getting in at the wall plate.

I have also seen water running down the inside of an external wall. In the early 80's I worked on a site which was in a very exposed position on a mountain side. You did get driving rain there, and this site had lots of problems with damp penetration. The problems were so bad they actually closed the site over a winter and they kept me there to sort out the damp problems.

I had to cut into cavities to find where the damp was getting in, and you'd be amazed how much water was running down the inside of the face bricks. One example, there were stepped trays on these houses, some owners didn't like the open perp on the bottom tray and filled them in. They then had damp getting in because of this. Cleaned the perps out, the damp was cured.

They originally had single skin brickwork on the garages but changed to cavity work because of the damp getting through.