Need a professional builders' opinion on my situation

[markyyyyyy]

Hi,

I have just had a new extension complete, and we have got suspended timber floors. I posted the other day about having cold air into our kitchen, and i have seen (behind a bit of plasterboard that the electrician broke off to find his loop for 2nd fix underneath the kitchen units) that i can see outside through an airbrick. The airbrick is obviously at FINISHED floor levelm as i can see it.

I've raised this with building control, and he said they've got their levels wrong with the air bricks.

I phoned the builder on Friday and he has only just got back to me today. He said that they only left one air brick exposed to allow air into the room (surely thats what windows are for). He said on the phone today that the put telescopic air vents into the other air bricks, to take the air below the joists. I didn't believe him as he said they put the telescopic air vents in when they were laying the chipboard flooring onto the joists.

This got me exploring a bit further, so i have smashed out a 3 inch section of plasterboard from where another air vent is, and i can actually see a black plastic vent of some sort, that does seem to point down to the floor.

Can a professional builder confirm if the telescopic air vents have to be installed as you go? ie. while brick laying? There is a big gap in the breeze block behind the plasterboard in the kitchen, hence why i can see some sort of black vent - but it has come loose so i can actually see right through to the air brick. My understanding is that the telescopic air vent should connect to the inside of the air brick, go down in the cavity and pop out the breeze block BELOW the timber floor, so technically all i should see behind the plasterboard in the kitchen is pure breezeblock, no gaps? This is why i'm getting cold air in.

I have attached a picture which is from the small bit of plasterboard i smashed out today - you can clearly see a big gap in the breeze block, a black plastic thing that looks like a telescopic air vent, and the air brick on the outer - isn't the telescopic air vent meant to be cemented in - so i don't understand how its come loose either. To give you an idea - you can also see our finished laminate floor and the copper gas pipe to the right.

Hope i have explained myself okay. I still feel the builder is trying to make a mockery of me.

Edit: I have also just remembered - they used clay cavity liners along with the airbrick - so to me this would be justified if the airbricks were situated in the brickwork BELOW the joists. It looks like they have used cavity liners and did a bodge job at the last minute by shoving in a plastic telescopic tube which isnt even connected to the air brick. I believe it is either air brick and cavity liner OR telescopic vent?

Thanks

Mark

 

[^woody^]

Nah it's all wrong.

Get the wall knocked out from the outside to check (and rectify). If the builder is right you pay, if not he does.

 

[markyyyyyy]

Nah it's all wrong.

Get the wall knocked out from the outside to check (and rectify). If the builder is right you pay, if not he does.

Cheers for the reply. So you're pretty confident i am right? It actually looks like they have removed the clay cavity liner to shove the plastic bit in, which makes sense why there is a big gap.

 

[Notch7]

Builders trying it on.

He didnt leave 1 vent to go into the room. A brick vent can be used as passive ventilation but it wouldnt be behind kitchen cupboards, nor would it be plasterboarded over. And such a vent would need a hit and miss vent cover.

Telescopic vents are fitted when the walls are built, sometimes they need to be done when a concrete block and beam floor goes in, not sure about timber floor joists. They wouldnt go in at time of chipboard floor -that would happen once room is built and weathertight.