Bricklayer problems

[deuce22]

Just come back from the site and I do think now that this Bricklayer doesn't know what he's doing.

I have given him the drawing that I got from the Radon report, so he can now visually see what the setup is.

He then started questioning the cavity tray, saying that it wasn't needed because the Radon barrier is fitted. Although the Radon barrier goes straight through the cavity at the same level as there are vents in the way. I told him that the cavity tray is formed to stop any water penetration into the inner wall, but he still disagreed with me.

He said that he doesn't always put a cavity tray in when he is doing new builds or ext and seemed to be getting confused between the purpose of a Radon barrier and cavity tray.

I am certain I am correct because I have been doing a lot of research, but he is making me question myself.

Cheers.

 

[deuce22]

No.

There was an issue with a main drain running through the site and there was a potential that it would cost around £30,000.00 to re-direct it or Welsh water would not let a building be constructed at all.

We pursued it and it ended up being a balls up by Welsh water. There was no pipe running through it at all.

 

[Ricke21]

Lol i've heard of far worst traders. If the detail of a cavity tray was the only way you could fault a bricklayer then i'd say he's good. Only needs to be directed!! I qualified level 1 & 2 in bricklaying and trowel occupation. A lot has changed in cavities, cavity trays and all sorts of new regs have been thrown in. I take an interest in it all and like to keep to date. This is not the case in all trades. Most that work for or on behalf off ppl.

 

[Ricke21]

oops that was in 1996 and a lots changed

 

[deuce22]

Hi Rickie21.

Can you confirm then that the sole purpose of a cavity tray is to stop water penetration into the inner wall and has nothing to do with radon protection.

Cheers.

 

[Ricke21]

Sorry had to google 'radon protection' which i understand to be the DPM? No deuce the cavity tray has nothing to do with it. The point of the cavity tray is so that water that condensates within the cavity will drip down and run out. Hence having them where you bridge a cavity (windows, doors, openings) and all the way round ground level.

Personally i wouldn't block and beam of the inner skin. It be better to throw dwarf walls up.

 

[freddiemercurystwin]

Sorry had to google 'radon protection' which i understand to be the DPM? No deuce the cavity tray has nothing to do with it. The point of the cavity tray is so that water that condensates within the cavity will drip down and run out. Hence having them where you bridge a cavity (windows, doors, openings) and all the way round ground level.

Personally i wouldn't block and beam of the inner skin. It be better to throw dwarf walls up.

Jeez this thread now has the blind leading the blind. deuce22, if i were you I'd bit the bullet and get some profesional help before this development turns into a complete disaster.

 

[Ricke21]

Blind for never using "Radon Protection" I'm a builder not a office bod!!

 

[freddiemercurystwin]

Blind for never using "Radon Protection" I'm a builder not a office bod!!

That is apparent, which is why you are maybe not in the best position to be advising someone with apparently even less knowledge? See? Blind leading the blind.

 

[Ricke21]

 

[Nige F]

IS there Radon in Wales Is the Pope Catholic - I just googled it - place is riddled with Radon -

 

[deuce22]

Hi freddymercurystwin.

I thought that was what I was doing employing a qualified Bricklayer and so-called Architect.

I don't know who else can help and I seem to be finding more info on the net and this site.

I have even had a couple of issues with the BCO who is employed by the council.

I had to tell him how I was constructing the cavity at floor level as he was telling me another way that had me cutting into the Radon membrane.
The second thing was, he told me to use either a thermal block or insulated plasterboard on the inner wall, even though I had 60mm insulation in a 110mm cavity.

Turns out that the U value was more than enough without any extra material.

Cheers.

 

[^woody^]

He said that he doesn't always put a cavity tray in when he is doing new builds or ext and seemed to be getting confused between the purpose of a Radon barrier and cavity tray.

In short, the radon barrier goes across the complete footprint of the building, including the cavity walls, and this is intended to stop all gas entering the building or cavity

Then a cavity tray (different material to the radon barrier) is put across the cavity and above the radon barrier to stop penetrating water tracking back across the [horizontal] radon barrier.

It depends on the detailing though, as to where they both go

An alternative may be to have the radon barrier lap onto the cavity tray

In any case, there would normally be a tray and a barrier

It is also important to have the ventilation below floor, and also the weep holes above the cavity tray.

This is a very important detail and you really should ensure that it is detailed properly (by the designer) and done and sealed properly (by the builder). You should not be expecting the builder to design this for you

 

[freddiemercurystwin]

The OP will be saying the NHBC inspector does not know his stuff next!

Eh? Wassat then?

 

[^woody^]

I have even had a couple of issues with the BCO who is employed by the council.

In your previous post, you said that the BCO is being paid privately - ie an independent.

So which is it?