vaulted ceiling on a lean to roof (new extension)

[houserenovating]

Hello All

I would really appreciate some informed opinions....

We are currently having a rear extension built, with a lean to roof. We want the interior ceiling to be vaulted (i.e. not horizontal) and the architect and builder said it would be fine.

The only problem is, the building control officer visited the site recently, once the walls were built (no roof supports put on yet) and told the builder that he needs to (a) put in horizontal beams in addition to the lean to beams, which needs to be bolted to the lean to beams AND (b) the ceiling must be under the horizontal beams (ie we can't leave the horizontal beams exposed).

Is this right???

I have seen extensions with vaulted ceilings which weren't built too long ago, and the govt planning website has building regs (which I don't understand!) were last published in 2004 - so I don't think there have been any very recent changes......

Thanks

 

[freddiemercurystwin]

If the design is anything out of the ordinary then a structural engineer may well be required to ensure your desires are realised, if Building Control are unsure of anything they'll have you overkill the structure to be on the safe side. Sounds like your architect/builder aren't too confident about what they're doing tbh. No idea why you can't have the ceiling against the pitch although tbh its quite difficult to usefully comment with the information you've provided so far. Include some spans/dimensions/pics etc.

 

[houserenovating]

If the design is anything out of the ordinary then a structural engineer may well be required to ensure your desires are realised
its quite difficult to usefully comment with the information you've provided so far. Include some spans/dimensions/pics etc.

The design is quite standard - the extension is an 'L' shape single storey rear and side, with a few small velux windows in the roof. Dims: 3m depth from original rear wall, 8.5m width along the rear of the property.

just examined the drawings and seems that the architect (despite what I asked for!!) has drawn a horizontal interior ceiling.

does the fact that planning permission was granted on these drawings mean we must now have the ceiling in that style?

 

[freddiemercurystwin]

No, planning won't give a hoot about the interior unless its a listed building. Unfortunately it sounds like your architects made a blunder, its no excuse but it does pay to always check the drawings though. I hope the scheme can be turned round without too much hassle/cost.

 

[noseall]

The only problem is, the building control officer visited the site recently, once the walls were built (no roof supports put on yet) and told the builder that he needs to (a) put in horizontal beams in addition to the lean to beams, which needs to be bolted to the lean to beams AND (b) the ceiling must be under the horizontal beams (ie we can't leave the horizontal beams exposed).

You won't need a purlin provided the rafters are strong enough with correct spacing.

You will need a pitching plate bolting to the wall although this could be positioned at the rafter (top) ends as opposed to beneath them.

You will need to insulate the roof. This could be done as a warm deck but will leave you with one heck of an ugly (very deep) fascia.

Alternatively you fix faux beams beneath the ceiling and build as vented cold deck, but this will look pants.

As Freddie has said, nowt to do with planning.

Sack the architect and flog the builder.

 

[jono_h]

As Noseall says!

I've done exactly this on my last two extensions and Building Control haven't batted an eyelid.
You have to allow for the fact that without a horizontal joist there will be some force trying to push the wall outwards, but this isn't difficult to overcome. (See Nosealls note about a plate to attach the rafters to)

I guess some areas are lucky with their BC officers!

 

[sbdobson]

What happend Johno H? I am planning a lean to vaulted roof with four velux windows. It hasnt been started yet but I am bit concerned. I know that the roof is going to want to push outwards. Plus the outer wall is a party wall line so I cant have an eaves/overhang. Its proving to be mere.
I have seen many lean to vaulted roofs before but dont know if they have been specified by an engineer or not.
The architect has planned roof structure and the builder seems to know his stuff but I am bit concerned as I know detailed calculations are not something architects know much about.

 

[Chukka63]

only read the first few lines and ive got exactly what you want, a vaulted ceiling in a lean-to roof.no problems.get a 2nd opinion if youre not happy with what the BCO is telling you.

 

[freddiemercurystwin]

only read the first few lines and ive got exactly what you want, a vaulted ceiling in a lean-to roof.no problems.get a 2nd opinion if youre not happy with what the BCO is telling you.