Air brick height

[Vijay]

Is it normal practice for the top of air bricks/vents to be at finished floor level/150mm about the ground level?

 

Would it be any different on a timber frame house?

 

Cheers

 

Vijay

[tonyshouse]

150 above finished ground level, this is independent of ffl, they can be higher and frequently periscope liners are used 

 

same for all, timber frame included

[ProDave]

The "normal" here with timber frame, is the air bricks are entirely under the ground floor joists I have never seen anyone use periscope vents on a timber frame house. I think it's a building regs requirement that the solum (the ground under the joists in case that's a Scottish term you don't recognise) cannot be lower than the ground level outside.

 

In my case, with 300mm thick downstairs joists then the thickness of an air brick, my finished ground level has to be at least 450mm below FFL. Along the front of the house where the ground level needed to sensibly be higher I have accommodated this with a small railway sleeper retaining wall to create a step down in level close to the house then filled that with stones, effectively making a sunken French Drain along the front of the house and leading round the side to where the ground level tapers off.

 

[Vijay]

Mine has been drawn as Tony says.

 

The reason I've asked is I want to try and get a FFL from the house next to my plot as the original datum mark that was on a post has been removed from the development. So I was hoping to work things out from his air vent

[PeterW]

1 hour ago, Vijay said:

Mine has been drawn as Tony says.

 

The reason I've asked is I want to try and get a FFL from the house next to my plot as the original datum mark that was on a post has been removed from the development. So I was hoping to work things out from his air vent

 

Go and find a fence post on it that is roughly the right height and arbitrarily mark a datum on it and use that ..!!

 

Unless you get a very picky planning officer who can not only prove yours is wrong and every other house was built correctly (read: highly unlikely) and has the correct equipment (read : total station) then as long as you're within 200mm or so you have nothing to worry about ..! 

 

If they have no datum to measure yours, they have no datum to measure anything else .....

 

 

[Vijay]

2 hours ago, PeterW said:

 

Go and find a fence post on it that is roughly the right height and arbitrarily mark a datum on it and use that ..!!

 

 

Roughly the right height as???

[PeterW]

2 minutes ago, Vijay said:

Roughly the right height as???

 

 As the house next door ..! 

[Vijay]

That's what I was hoping to do and wondering if I could work from the airbrick height?   As you said, I want to be around the right height but I need something from the neighbouring house to work from

[Brickie]

So-are you trying to establish what height your neighbours air brick is in relation to their own ffl? Most of the time on housing developments the air brick would be laid in the last course below dpc so,by rights,top if air brick should be near enough ffl. If you follow the height along the wall to a doorway that should help-doors are traditionally sat straight on dpc level (until very recently when the fashion for level thresholds & patio means dropping the frame down one course. )

[Vijay]

Hi Brickie,

 

Yep, that's exactly what I need to work out so I can get to roughly the same height

 

Vijay

[Brickie]

Can't you set your level up in the road,knock on the neighbours' door & ask to take a reading off their floor & transfer it then?

[Vijay]

The development is off the main road by a fair bit. I can ask the neighbouring plot but he can be up his own arse so I'd prefer not to ask him anything if I'm being honest

[PeterW]

Get a laser level that has a spot point and set it up to aim at the top corner of a window on the neighbours house. Then count down the bricks to an air brick or to the level of the front door threshold. That will give you 75mm x  number of bricks that your level is above his house FFL. 

 

Spin the level round and then mark off onto a length of timber, measure down to Xmm and you have your FFL. 

 

 

[Vijay]

I'm pretty certain I can see an air brick on the side of his house so can do the laser level thing straight to the top of his air brick

[ProDave]

I am struggling to understand what the point of this question is?

 

surely you will set the FFL of the house to match the ground levels either existing or proposed on your site.  I can only assume if you must set your FFL to the same as next door, then this must be a planning condition, and the difficulty you are having to establish that just shows how difficult it would be for the council to also establish that and check if you have complied or not.
 

[Vijay]

My plans have FFL marked on them but I need to set a datum point. There was a datum mark on a fence post that the other two houses worked from but they removed it (for some unknown reason). So the easiest way (and cheapest) is to take a known point from the house next to mine to set a datum point for me to build from.