Ridge Beam Support?

[Liam Von Dork]

Hi , I’ve a 1760 stone cottage , well basically it’s a bungalow with two small bedrooms in the loft,with a staircase that may as well be a ladder.

I have literally gutted the entire property back to granite and brick external walls , I have removed the one supporting wall that ran across the middle of the property and replaced it with an RSJ, I am a qualified bricklayer but my roof building knowledge isn’t good.

The cottage is 7x5 mtrs with a 6x3 mtr flat roof extension at the rear.

There are four purlins , two each side of the cottage roof and are 7 mtrs long, they are supported by doubled up 8x3 C16 bird mouthed uprights , all bolted together.

I have created a new mezzanine style floor out of 8x3 joists all bolted into a granite wall with 150 mm anchor bolts where one bedroom used to be and the other side I am having vaulted with a small spiral staircase leading to the bedroom.

I hope you’re all following me so far.

My question regards the ridge beam/plate which is basically two bits of wood butted up against each other ,well almost , there’s a 10 mm gap and under the ridge beam is another bit of wood also butted up to another bit which in essence forms and inverted T shape, the lower bit of wood only touches the ridge beam in two places and I can run my hand pretty much all the way along it between the two bits of wood.

One side of the ridge beam is supported by the 8x3 uprights and I have no worries there , but the other side where I’m having the vaulted ceiling there seems to never have been any support as the original brick wall wasn’t even touching the ridge , there was enough gap for me to get my fingers through.

I am wondering if i remove the lower bit of wood and replace it with something more beefy and stitch it all the way so there is at least two mtrs of new 8x3 wood either side of the gap in the ridge beam will this be up to the job.

I’ve spoken to roofers and the opinions are devided, two say what I want to do is perfectly fine but one says the front of the roof will lift and or spread , but I can’t see how one side can spread if the other side can’t.

Hope I’ve explained it clearly enough.

Thanks
Liam

 

[noseall]

I'd be happier seeing either a steel ridge or some steel purlins on the non-mezanine bits - i.e. those parts of the structure bereft of floor joist restraint...

I would be inclined to get the opinion of an SE.

 

[Liam Von Dork]

I'd be happier seeing either a steel ridge or some steel purlins on the non-mezanine bits - i.e. those parts of the structure bereft of floor joist restraint...

I would be inclined to get the opinion of an SE.

Thanks for the reply, do you mean a continuous steel ridge beam or the plate underneath it, which I could get at fairly easily?

Steel purlins are not an option , we want to retain as much originality in the cottage as we can.
I will have replaced the two top purlins on the side you’re talking about with new 8x3 timber.

I have also been in contact with firm who can/will tell me what’s what if I send them photos .

The Rsj I installed has at least 500 mm of bearing on each end , that’s going nowhere and it’s cemented in place.

 

[noseall]

The Rsj I installed has at least 500 mm of bearing on each end , that’s going nowhere and it’s cemented in place.

This could be your savoir. Can something be done that uses the steel beam to form a kind of in-fill truss that will ultimately support the purlins and ridge beam?

 

[Liam Von Dork]

This could be your savoir. Can something be done that uses the steel beam to form a kind of in-fill truss that will ultimately support the purlins and ridge beam?

I have bird mouthed some 8x3 c16 timber and doubled it up , screwed it together with 120 mm timber drive screws and also screwed each purlin into these bird mouths,as far as I’m concerned there is more support than the 260 yr old single skin brick wall that wasn’t even touching the purlins or the ridge anyway,I could get my fingers through everywhere that is was supposed to be touching, two of the purlins had been cut in half and removed some years ago , so the whole place is a lot more supported than when I bought it anyway.
The ridge beam (almost ) joins a bit of wood That is also in two sections and only had 50 mm of support in the form of the old brick wall anyway , even though it wasn’t touching it.

I could not put my RSJ where the old wall was as I wouldn’t have had enough space to build a wide enough pillar to support it , as I like my pillars to be as wide as they are long, gives me peace of mind.
This is the cause of the issue as there is no support immediately under the wood that sits below the ridge beam , which does run some 400mm past the join in the bit of wood below it, but like I said it wasn’t touching the wall anyway