Vault ceiling options

RamboArnie

Hello,

Is it possible to build a vault ceiling by just using a structural steel RSJ as a ridge beam? Was going to go for the "exposed" roof truss look, then someone mentioned to use an rsj as a ridge beam.

Which is best option, structurally and also cost wise?

Any advice welcome!
Thanks

Gumbo

RamboArnie wrote: »

Hello,

Is it possible to build a vault ceiling by just using a structural steel RSJ as a ridge beam? Was going to go for the "exposed" roof truss look, then someone mentioned to use an rsj as a ridge beam.

Which is best option, structurally and also cost wise?

Any advice welcome!
Thanks

Ask your engineer.
You need to contain the pancake spreading of the roof rafters and either a steel ridge beam or wall plate steel can do this. Both have pros and cons.

I went for the wall plate steel as it cut out the flat portion up at the apex.

But get your engineer in early as the wall build up can have a lot to say here and if you get to that stage and bring the engineer in later then it could cost more to get the result you want.

Calahonda52

As above: steel ridge board on its own wont work as it provides insufficient lateral support as described by KC.
Steel wall plates easier but I always make sure its a rectangular structure so you will need to hide the two cross pieces at the ends because the steel wall plate transfers the lateral load onto the wall which wont restrain it on its own.

RamboArnie

Thank you for the replies.

Apologies for my lack of understanding! But when you mean steel wall plate, does this mean an RSJ, running along the top of wall, at wall plate height?

Currently have a small pvc conservatory at rear of house. It has a perspex roof, and pvc windows both sides of walls. We are looking to build up the walls and placing just 2/3 smaller windows either side and double doors at gable end, to make it more of a garden room. The perspex roof being removed and a new roof constructed with concrete tiles.

The vault ceiling was just something we are deciding on. Also going self build. The neighbour getting work done so we asked the roofer on the job to have a look. He just mentioned we would need a load of steel to achieve what we are looking for. I'm just trying to picture it how it's constructed.

Cheers

Calahonda52

Some folks use RSJ's
others use box sections, it depends, its generally a rectangular frame so not just two pieces on the walls

What is the floor area here?
What is the existing wall construction?
Are you happy foundations will take the extra weight?
What is the extra height being added?

You also need to figure out the roof insulation before you get a roofer to just slap it up.
https://www.nsai.ie/S-R-54-2014-Code-of-Practice.aspx
may help

Will full solid roof make inside room v dark?

Gumbo

Sample of what we done.
We were slightly restricted in that the Neighbour nest door built using cavity blocked so we didn't want to put any load from the roof onto the existing party wall.

Gumbo

We used box sections as wall plates tied back to the frame holding up the existing house, to achieve this end result.

sydthebeat

kceire wrote: »

We used box sections as wall plates tied back to the frame holding up the existing house, to achieve this end result.

Was that tree light your choice kceire?

Gumbo

sydthebeat wrote: »

Was that tree light your choice kceire?

Believe it or not, my dad came home with it one evening. Didn't even tell my Mam, and everyone comments on it!

chillit

Hi keire. Very nice finish. Can I ask about your large sliding door. Do you use this a lot and based on your experience would you recommend a door like this for use on a daily basis? I.e. if we used it like a main back door for coming in with shopping etc would you recommend it.

Gumbo

chillit wrote: »

Hi keire. Very nice finish. Can I ask about your large sliding door. Do you use this a lot and based on your experience would you recommend a door like this for use on a daily basis? I.e. if we used it like a main back door for coming in with shopping etc would you recommend it.

Used everyday and with 5 grand children running in and out.
No problems so far touch wood.

chillit

THanks for the feedback. I'm currently trying to decide between large slider and bifold. Did you ever debate a bifold or was it always a slider

RamboArnie

Calahonda52 wrote: »

Some folks use RSJ's
others use box sections, it depends, its generally a rectangular frame so not just two pieces on the walls

What is the floor area here?
What is the existing wall construction?
Are you happy foundations will take the extra weight?
What is the extra height being added?

You also need to figure out the roof insulation before you get a roofer to just slap it up.
https://www.nsai.ie/S-R-54-2014-Code-of-Practice.aspx
may help

Will full solid roof make inside room v dark?

Thanks for reply.

The area is 26m2 (its big)
Existing wall structure is standard cavity wall construction
Foundations are also standard, 900x300mm..where poured about 5years ago
Extra height will be at about 2.5m at wall plate level
2 Velux's will also be added to each side.

RamboArnie

kceire wrote: »

Sample of what we done.
We were slightly restricted in that the Neighbour nest door built using cavity blocked so we didn't want to put any load from the roof onto the existing party wall.

Thanks Kceire. That's a nice end result to your project. Looking to do something similar but without the glazing above the doors.

We where hoping just to add a ridge beam, build up the walls and place wall plate on top, maybe with some steel rod bracing inside?

Without creating a portal frame, would it be possible to build up piers at gable end to hold steel wall plate?

Found this pic on net.

RamboArnie

Anyone got a rough estimate on how much an engineer would charge to design and size the steel work? Just to prepare drawing and steel sizes?

Cheers

Calahonda52

A portal frame is something else entirely, so lets get the jargon correct.
The Portal frame has no tie/collar at eaves level and all the bending moment is taken at the rafter/stanchion joint.

I mention it only so as you don't ask fir the wrong design
.
Yes you can do what is shown in the image, assuming you can get someone to sign it off.

I just find the rectangular frame easier to design as there is no real design because the basic steel sizes are such that they will do the job...its hardly a 915 by 305 by 388 UB!

It may cost you 2,500 as the sign off alone will be c 850/1000 so may be easier to get the beam sized by the engineer and then let someone else draw it up.
Make sure the engineer sees it installed before it gets covered, else he wont sign off

RamboArnie

Thanks for that Calahonda52

Gumbo

chillit wrote: »

THanks for the feedback. I'm currently trying to decide between large slider and bifold. Did you ever debate a bifold or was it always a slider

Bi-fold never entered the equation for this.
I understand them but I don't personally like them.

Frogeye

kceire wrote: »

Bi-fold never entered the equation for this.
I understand them but I don't personally like them.

Kceire

Photo looks great. what dimensions are the sliding doors?

Looking at something similar in a new build but can't make up our minds...

Thanks

Frogeye

Gumbo

Frogeye wrote: »

Kceire

Photo looks great. what dimensions are the sliding doors?

Looking at something similar in a new build but can't make up our minds...

Thanks

Frogeye

5.2x2.1
From memory. I'll measure later.