roof spreading

[cdo1664]

Hi all

I live in an 1850 stone built cottage with an attic bedroom i'm insulating the roof and have discovered the roof rafters run into the walls and there is no rafter tie so can i assume that the wall is acting as the tie to stop them spreading. The walls are about 20 inches thick and solid stone. Any advice would be greatly appreciated.

Pete

 

[freddiemercurystwin]

If you were to examine any small property built before say 1970 you could easily find that it may not comply with modern standards yet they work as intended and protect the inhabitants from the elements just as well as their modern counterpart. Are the rafters supported with purlins in the loft? What exactly are you concerned about?

 

[cdo1664]

Thanks for your reply, the reason i asked the question is that before insulating the roof i did some research on roof construction and my configuration did not match those i found o the internet. There are two sets of purlins on either side of the roof 1 at about 1m and the other at 2m, the ones at 2m have cross members running betwen them to each rafter which, i assume, were the support for the attic room ceiling. I would like to remove these cross members, or at least some of them to give a vaulted ceiling effect but am a little concerned that it may effect the roof integrity. What do you think.

Many Thanks Pete

 

[freddiemercurystwin]

Ahh, the plot thickens!!! Can you post a photo or a sketch? Firstly you realise that removing/altering the structural elements in your house requires Building Regulations approval? This will quite possibly also trigger the need to employ a structural engineer! So assuming I get your drift you are making a vaulted ceiling for the rooms beneath the loft and wish to have it clear of cross members (ties)? If so had you considered leaving them in situ, this can be a nice effect depending on the look you are trying to achieve/the condition/appearance of the existing ties. Anyway, post a photo/drawing and we'll go from there.

 

[cdo1664]

Hi, I will post a photo as soon as i can, I would be happy to leave half of them in place and have the effect you talked about but to leave them all there would not really open up the space as much as i want to ( they are only about 40cm apart). I have read in similar forums that one tie to every three rafters is suffcient and if i did remove the cross memmber i would place a tie further up. The last thing I want is to go down the route of getting a structural engineer in to tell me that the roof, which has stood for over a 100 years is now not up to code and the whole thing needs to re-built. What do you think.

Many Thanks Pete

 

[freddiemercurystwin]

An SE is not gonna condemn your roof unless he thinks it is literally about to fall down, in which case that would be good to find out don't you think? As mentioned removing some of the ties is probably structural and as such notifiable work (ie requires Building Regs) so unless you want to do it illegally you won't have much choice. It will be difficult for anyone on a Forum to categorically tell you what you can and cannot do, even if you provide everything. ie, spans, ceiling tie sizes & centres, rafter sizes & centres, pitch, purlin sizes, purlin positions etc etc. Wouldn't it be better to have an SE confirm you are Ok to remove say every other one or whatever rather than some bloke (not me) on a Forum have a guess?

That said if you post some photos and all of the information suggested above in a new thread in the Building Section you might spike the interest of one or two of the engineers who frequent the site!

You do realise that if you ever come to sell and the surveyor picks up that some ties may have been removed he will spark the interest of the buyers solicitor who will request a Building Regulations Certificate?

 

[cdo1664]

Thanks for the advice, I will do as you suggest and seek advice from an SE, many thanks for taking the time to help.

Pete