Telescopic Air brick in solid wall

[arranp]

Hello All

I have just bought a property and discovered that there are no air bricks to the suspended sub-floor.

The exterior ground level is higher than the sub-floor but not above the dpc so i want to use a telescopic vent to provide ventilation to the sub-floor. What is the best way to go about installing a telescopic air brick into a solid wall construction?

If there is a better solution to using a telescopic brick please advise.

Thanks in advance
Arran

 

[jeds]

Victorian bricklayers would have turned bricks on edge to form what they called a rat trap. Easy to do during the build - less easy to retro build. Could you hack out the internal skin bricks and fit a modern plastic tele vent into the recess?

 

[arranp]

Hello Jeds

The bricks are in a Flemish bond pattern so there is no cavity to install the vent.

I was thinking about removing a section of bricks and cutting them to introduce a cavity so that the vent could be installed. I am just unsure if this is the suggested method and how many bricks I can remove without putting to much stress on the surrounding bricks.

I would ideally like to work from the exterior wall to install the telescopic vent, as the interior has recently been re-plastered.

Thanks

 

[RNReindeer]

A wide horizontal (i.e. more than 2 bricks wide) by shallow vertical hole would present more of a problem than a narrow horizontal (less than 2 bricks wide) by deep verical hole.
As your vents are only 1 brick wide, you don't need to go wider than 2 bricks max.

A disc cutter or series of drilled holes will facilitate the process, certainly for the visible face of the hole.

 

[noseall]

You need to make a hole through to the floor void at low level then form a troughed recess in your exterior paving. This trough can be fitted with a makeshift grille to prevent leaves etc.

 

[arranp]

@RNReindeer
Thanks for the info sounds like the hole I want to cut to place the telescopic vent should be fine. I will give this a go on the weekend, thanks for your help.

@noseall
I had thought about doing this but I don't want the surface water run of to go into the subfloor.

 

[arranp]

Hello RNReindeer

I have just realised as I have a flemish brick pattern to make the void I will need to cut through the the bricks spanning both brick layers (perpendicular to brick face).

The cavity will still only be single brick wide ,but as I am removing the strength added by these bricks will this result in substantial affect on the brick layers ability to move apart?

Thanks

 

[RNReindeer]

As a DIYer (Noseall and others are the pro's) I'd say that there will be no detrimental effect. The headers above, below and beside the holes will be adequate.

BTW, are you aware that you need a through flow? So you'll need to do likewise on the other side of the building.

 

[arranp]

Hello RNReindeer

Yes I am aware I need air bricks on either side, thanks.

Unfortunately the front of the house has a wider space available to place ventilation so I can adequately space the air bricks while at the rear of the property I will have to place the 2 brick about 60 cm apart .

Thanks
Arran

 

[jeds]

Hello Jeds

The bricks are in a Flemish bond pattern so there is no cavity to install the vent.

I was thinking about removing a section of bricks and cutting them to introduce a cavity so that the vent could be installed. I am just unsure if this is the suggested method and how many bricks I can remove without putting to much stress on the surrounding bricks.

I would ideally like to work from the exterior wall to install the telescopic vent, as the interior has recently been re-plastered.

Thanks

I didn't mention a cavity. One brick thick bonds (apart from header bond) are built from two skins of brick with a collar joint between and through bricks to make the pattern - Flemish, double Flemish etc. To form a vertical vent Victorian bricklayers turned the inner brick on edge leaving a 50...ish mm void between the inner and outer skin. The external bond is maintained by snapping bricks. (snapped headers)

I wasn't suggesting you do that because it would be too messy to achieve but what you could do is remove a couple of inner bricks (which would leave a recess in the brickwork) and set a tele vent in their place. Although you might not want to do that since you now mention the new plaster.

 

[oldbutnotdead]

I tried the same trick- there isn't enough room in a solid wall for those plastic things.

So various different airways have appeared;
1 All 3 inner courses opposite the airbrick chaindrilled out. Split the bricks down the middle (anglegrinder) and make 2 little plinths for the bottom course where the inside of the airbrick is meant to be. Half depth slate on top of the plinths, mortar the split bricks in the hole and away

2 50mm core drill from the outside at about 60 degree angle (use a long SDS bit as a pilot so you get the line right). When you get bored of pulling the core bit out to remove chunks of brick, drill through horizontally from the inside to meet the hole, cover outside of hole with mesh (rats!). You'd need 1 of these per metre to get adequate airflow and it is a really tedious job

Good luck- it is all a bit of a pain. No pics either

 

[jeds]

there isn't enough room in a solid wall for those plastic things.

A plastic tele vent is about 45 or 50mm deep x 215mm wide. An imperial brick is slightly wider and quite a bit deeper. That's plenty of room.

 

[arranp]

@oldbutnotdead - thanks for the advice , i am going to try with the telescopic brick first as it does seem like the measurements will work. If not i will give your method a go, seems like a good alternative.

@jeds - thanks I agree the bricks do seem big enough to accommodate the telescopic vent.

Thanks all for advice.

 

[mattwaddy]

Reviving this thread to see how you got on, I need to do the same thing i.e recess one of these in a solid single brick wall, the other in a cavity. Just wondering if you chased the depth out or removed the bricks and split/cut them in half