How to redirect air vent which is in line with where new wall will go

[jimmy342]

Hi,
I am building a conservatory and now that the foundation have been laid I have noticed that one of the air bricks on my existing wall will be in line with the inner leaf of the wall of the conservatory. So how can i extend this vent to the rear elevation of the conservatory without having to tunnel it under the wall? Moving the vent along on the existing wall would be a big job as will need to knock out several bricks to put in a new telescoping vent through to the inner leaf of existing wall and block up the existing hole in both the inner leaf and outer wall. Is there an easier way to get this vent extended out to the new wall of the conservatory without moving the location of the vent in the existing wall?

 

[^woody^]

A pipe under the floor to the new rear wall is the normal way

 

[jimmy342]

i can run a pipe under the floor but it will not mate with the air brick because the air brick is where the inner leaf of the wall will go as can be seen in the pic. As per my measurements about half the air brick will be covered by the wall. Would it be sufficient to angle the pipe out of the airbrick at 45 degrees under the first block so it is under the floor and then run it parallel to the wall to the rear elevation? I suppose this will not affect air flow? thanks

 

[^woody^]

You bang another hole through to the side of it and duct it straight, not on an angle.

 

[jimmy342]

OK thanks. Just wondering that if it is a telescoping vent on the other side it will not ventilate properly unless i also put the vent through the inner leaf to the underground ventilation. Also does the pipe that goes to the rear elevation of the conservatory, does it need to be protected to avoid being crushed under weight of floor?

 

[^woody^]

Knock a hole though the whole wall, shove a 100 mm pipe through into the under floor void and then gob the hole back up. At the other end, get a round to rectangle duct connector, and connect that to a persicope vent that goes in the new wall and exits to an air brick just below the DPC. The level of the pipe can be below or within the hardcore, then a bit of sand on the top and then just membrane and concrete over it. Slope the pipe slightly back towards the house to prevent and moisture build up inside it.

 

[jimmy342]

OK thanks for your help.

 

[jimmy342]

Just another question. Do the existing air vents need to be removed and replaced with solid bricks for structural integrity or is it ok to leave them in place? Asking because by removing the existing air bricks won’t it damage the dpc that sits right above them and then cause rising damp in later years? Thanks

 

[^woody^]

You can just block them up and go over them.

 

[jimmy342]

Thanks. Is 2.5inch pipe sufficient or do I need to use a 4 inch pipe? I want to make a small a hole as possible. Thanks again.

 

[^woody^]

Thanks. Is 2.5inch pipe sufficient or do I need to use a 4 inch pipe? I want to make a small a hole as possible. Thanks again.

You will need 4 x 2.5" pipes to provide the required amount of ventilation.

I don't know why you are worrying about the size of the hole.

 

[jimmy342]

Ah ok. I am just worried about the structural integrity of the wall with such a big hole below the air vent which itself is already a hole in the wall. I presume there should be no issue if a couple of bricks are removed and a 100mm pipe is put in. Wall should not weaken and crack over time right? First time doing this so want to ensure will not cause a problem in future.

And did you say the pipe should slant towards the house or away from the house ?

Also do I just knock through the current plastic telescopic air vent that is currently there or put a hole into the telescopic air vent and insert the pipe into that.

Thanks for your continued replies on the topic.