Garage floor level??

[RichS]

So as I understand the building regs, with an integrated garage there has to be either a 100mm step down from house to garage, or a level access with the garage floor sloping away from the garage/house access.

Does anyone know what is the minimum gradient for the slope. It doesn't seem to get a mention anywhere.

[Tennentslager]

Read on another post on Ebuild that the reason behind this reg is in case of a fuel leak in the garage.

So logically not much of a slope needed...10° maybe? Just a guess.

[Steptoe]

I'd hazard a guess fumes also play a part,

In a commercial garage with a pit , that pit becomes an explovsive atmospherere due to fumes gathering there, 

[Steptoe]

Oh, and I think you need a fire door too,

You may already know the answer to that 

[Vijay]

Do you have to have an air brick/vent too with an integrated garage?

[ProDave]

You definitely need a fire door. In Scotland there is no option for a level threshold, you must have a step. A single garage does not need vents, but a double one will, I forget what size triggers that need.
 

[RichS]

Thanks for the replies.

Yes, I know the adjoining door has to be a fire door.

I hadn't picked up on the air vent so will look into that.

As for gradient I was thinking more of a 2 degree at most, with a 10 degree I have visions of jet washers /  compressors etc etc all rolling out every time I open the garage door

[PeterW]

2 degrees is fine - just watch where you put your door and threshold drain as it needs to be aligned or you can get rain running down the front of the door and under the edge. 

[Temp]

+1

 

5.4 , 5.5 and diagram 10 don't actually mention the required slope. 

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/485420/BR_PDF_AD_B1_2013.pdf

 

1:40 is usually the minimum recommended for draining water off a pavement and that's 1.4 degrees.

[RichS]

Thanks for the input.

Just done a bit of working out and even it I only put approx 0.6 degree fall onto a floor slab of 8.7m it will still be a differential of 87mm. I may as well just go with the 100mm step and a level floor.

Does anyone know where the air vent to garage gets a mention in building regs, English version??

 

Edit

 

Thinking about it a bit more. The build will be in ICF with a render finish and so I don't want to put in an air grate.

If I was to put in an extract from the MVHR unit surely that would satisfy building regs.

Edited December 27, 2016 by RichS

[Vijay]

Rich, I'm in the exact same position, building in ICF and don't really want a vent in my garage/workshop

[Guest Alphonsox]

2 hours ago, RichS said:

 

If I was to put in an extract from the MVHR unit surely that would satisfy building regs.

 

That would potentially pull fuel vapour into the house which doesn't sound like a good idea. I doubt building control would go with this as a solution - you are trying to isolate the garage from the rest of the building. 

How about a vent in the garage door if you need one ?

[Steptoe]

21 minutes ago, Alphonsox said:

 

That would potentially pull fuel vapour into the house which doesn't sound like a good idea. I doubt building control would go with this as a solution - you are trying to isolate the garage from the rest of the building. 

How about a vent in the garage door if you need one ?

 

would totally agree with that,

I'd be fairly sure the vent has to be low level, the idea is to vent noxious fumes, (which are heavier than air), out,

 

[RichS]

Ok, can see your point on this.

So does anyone know where this air vent is mentioned in the regs please??

Presumably somewhere in Part F.

Edited December 27, 2016 by RichS

[ProDave]

Scottish regs says in a garage large enough to need vents, it needs two at low level and two at high level.
 

[RichS]

16 minutes ago, ProDave said:

Scottish regs says in a garage large enough to need vents, it needs two at low level and two at high level.
 

At what size???

 

I've just been through Part F and can't find any mention of garage ventilation in the English regs