Roof Vents and Building control

[adrok]

Hello DIYnot community,

I'm after a bit of advice, I am converting a double garrage into a study/office, thought I'd do it right and get building control notified etc, all is fine apart from the nice lady said i need 25mm free air ventilation as the roof (pithced) is unvented.

She told me to put plain tile vents in as per the instructions to get enough flow etc, so I looked into it but many vents will do 6mm so I would have to put in 1 every 28cm on each side of the roof plus 5mm equivealent in the eves, at £20 a pop it seems excessive as the roof is 5metres long

Is there a cheaper way of doing it?

Any advice would be great.

 

[freddiemercurystwin]

Assuming the existing fabric allows it, stick some circular vents in the soffits, keep an air route open between the soffits and roof void above the insulation at ceiling level.

 

[adrok]

Hi Freddymerctwin

The problem is that there is no soffit the fascia butts up against the ends of the rafters as per diagram, I had thought of routing a groove in the fascia but was worried about water / rot, or thought about extending the fascia out , but I dont know if it is doable?

Untitled

• adrok
• 30 Sep 2011
• 1

 

[freddiemercurystwin]

Yea you're a bit short on solutions there, that's what I meant about the existing fabric allowing soffit vents. You can get vents that go between the tiles and the gutter, again assuming the fabric lends itself to that too. But that's probably as expensive as the tile vents.

Are you sure you'd need that many tile vents I normally spec about 3 each side and that always gets approved by BC.

Extending the fascia out is probably not possible as your tiles would no longer be overhanging the gutter by as much. Depends. Fair bit of hassle though.

 

[adrok]

Hi Freddy

what about this http://www.manthorpe.co.uk/SiteData...ation/MBP 8011 - G2500N OVER FASCIA VENT.pdf

on the face of it this seems like the answer, I too thought that the building control ladys need for vents was excessive you would think that a couple would do the job but not so according to her!

this over fascia vent looks like the kiddy as I can just remove the board cut it down and re fasten it? 5 mins max! quite cheap in comparrison too.... which is a surprise.

 

[freddiemercurystwin]

Yes that's what I meant by

You can get vents that go between the tiles and the gutter, again assuming the fabric lends itself to that too

 

[adrok]

Awesome

Job done thanks for your help!

they look like a doddle to fit and I reakon it will work!

 

[datarebal]

over fascia vents....klober

 

[Mw Roofline]

Plus you downsize on the fascia board to allow for the thickness of the vent saving you a few quid