Reply With QuoteA few pictures would help
On the of-chance, if I could run something by someone.We have a gable end wall to our kitchen, and looking to remove the ceiling to vault the ceiling.
Poking around in the loft, We've a slightly strange set up on our ceiling joist arrangement, where the joist don't run in the same plane as the rafters, so effectively no rafter ties. There is 1 beam that runs between the rafters at mid point, and is therefore not a rafter or collar tie.Anyway, its about the feasibility of removing this, and moving it further up in the vault, and in combination of adding more of them, and also using lateral restraint ties from wall plate down, on both opposing walls. For reference , its a width, or depth of 8 ft of rafters at 14' centres.....
A few pictures would help
Sure. Incoming
Sent from my iPhone using Tapatalk
For context, ceiling/ joist height to ridge is approx 1100 mm. Cross beam is 600 mm, so Heather in lower 3rd to be a rafter tie or upper 3rd to be a collar tie.
The beam at the gable end can stay.
The king post/ support post nearest you can see( and circled in red on plan) is down on a supporting wall. More supports/frame to be added and stud wall created to mirror gable end. It’s that mid beam that would ideally move.
Was thinking of my e adding collar ties to every rafter a foot down from top of ridge, and also having lateral restraint ties on both opposing walls.
On the plan, you can see the kitchen at the rear, the wall to the left has a wall coming of this - part of house which no doubt gives that strength from any deflection, the opposing side is the return wall of property. The corner return again will be sting being tied in , a the beam looking to come out is 4 ft/1200mm away from this corner, so wondering if that could cause issues with spread. The width or depth of the ceiling/room is 8ft/2400mm, distance between walls 3600mm.
That roof structure is a little bit odd for its age, but is not that unusual.
You really do need a Structural Engineer to visit with 'eyes on' and make recommendations, as whatever you alter up there needs to consider the roof spread as well as the other complications such as the valley which can be seen in one of the images.
There are many ways this can be overcome structurally, but the changes need to be assessed 'in the round' rather than as isolated changes to individual structural members.
Also, not a structural issue, but you will need to consider how the interstitial condensation is dealt with when you move the plaster and insulation/finishes up the roof slope when you vault the space. Again, relatively easy to resolve but it does need thought.
Indeed. I’m pretty sure it’s an extension added at a later date. Unusual for ceiling joist not to run in same direction as rafters to work as roof ties. Can’t really see what’s preventing too much spread at the minute. The is that T junction wall to the left, effectively acting as a buttress.Originally Posted by Maysie
Valley end has no support anywhere, other than where ridge is cut in, and that king post sitting on a joist on the supporting wall.
I’ll check out and see if there’s any SE’s locally who are mot going to charge several hundreds for suggestions.
Thinking a roofing/framing contractor who is hands on will have a sensible conversation about it in layman’s terms.
There is no insulation anywhere in that kitchen area. Nothing above ceiling, and nothing at rafter level. Another opportunity to gain some building reg’ level insulation in there…
Last edited by deanlad; 25th October 2023 at 12:28.
Again, for a bit more context, hers an old photo of back of property. Dotted line is ceiling joists. They do not support anything as run opposite to rafters.
Lines I’ve marked illustrate the corners. The one to the right kicks back along the rest of Orangery, so I would assume a buttress effect, so maybe no issues with spread there?
The return from the left side runs about 9 metre to front of house. The solitary offending beam is 4ft/1.2m away from that corner.
Again, I’d like to naively think the strength from the brickwork being tied in on a 90 degree return would give more stability against spread rather than it being metres further down in the run of a wall…
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
If the roof was built as an extension to the main property, I would have expected to see the rafters cut onto layboards placed above the rafters of the original roof slope - not built using a valley timber - as you have.
The propping post and collar ties are helping to reduce the resultant lateral thrust from the roof. These forces need to be resolved by another method to allow what you want to achieve. Raising the collar ties as you want to do, places the rafter under increased bending moment forces - which they are not currently withstanding and are probably inadequate to resist without strengthening or other intervention to remove the lateral thrust (eg a ridge beam).
You are making structural changes to your property, which require Building Control approval, you are very unlikely to get that without involvement from a SE anyway, so it is better to just pay for the advice and know what you are doing has been done properly.
As I said above, you need to take advice from a Structural Engineer. Roofers/carpenters are not structural engineers.
If you don't think that is worth paying for, then obviously that is your choice.
Thanks again for this. I do have an SE on the case, just waiting for her to get back, but in the interim, seeking what others may suggest.
The support post is staying in place, the collar tie is staying at the gable end, it’s a solitary beam in the middle that is potentially moved. However it seems like like this single piece is the one that supporting the entire roof from what you’re saying?
The ceiling joist have no connection or offering any support to anything, as they are not attached to rafters, or wall plate.
As you can tell I’m not an expert on this matter, but I am an overnight internet expert. I’m a little confused by definition of collar tie - upper 3rd, rafter tie lower 3rd, or ideally as low as possible to wall plate, yet these fall as neither?
Collar tie prevents uplift, rafter tie, spread, so maybe I should be looking to introduce further support which is not there already?
I think you may have lost your way with your 'Google-learning' based on some of those definitions and explanations.
Eaves Tie
Collar Tie
Ceiling Tie
Raised Collar
Clasped collar
Ceiling Joist
Ridge beam vs ridge board
Rafter
Common rafter
Principal rafter
They all mean slightly different things and are often confused, but some can be used interchangeably dependant upon how the roof is detailed, jointed and structured.
I am not too worried about the ceiling joist removal, it is moving/removal of the collar ties, prop post and its supporting beam which would worry me, as well as the apparent lack of bracing and removal of the apparent limited restraint currently in place to the gable masonry too.
Glad to hear you have a SE involved though.
I will shut up now as I may confuse matters more by replying further!
Last edited by Maysie; 26th October 2023 at 14:19.
Me up Scotty
Sent from my iPhone using Tapatalk
No, Not at all. Its one of the only ways to learn from experience and knowledgable sources.I guess as you point out some of the mane can reference dual/multiple situations.
Im guessing it would be an option to lose the beam in the middle, but introduce 2 new ones say 2 foot either side, of the one looking to move? They could also be moved lower rather than the existing height?
I have some hollow replica oak beams which would house these. I need symmetry , hence looking to remove or relocate with more... Ill post a couple of more images later...
Would lateral restraint ties fixed across the rafters and with noggins placed between rafters, work, with the return of the tie fixed to gable brickwork? There could be 2 placed per side, upper and lower? Has to be better than what's not already there...
Last edited by deanlad; 26th October 2023 at 20:43.
Going for this kind of look. Ideally beams would have run in opposite direction, as only 8ft in length. If they run in opposite direction will be 3.5 m in length.
Sent from my iPhone using Tapatalk
Last edited by deanlad; 27th October 2023 at 09:38.
Posting Permissions
