Steel/Catnic lintels for wide span ope's

Jollyman

I have a few wide opes in my house which i am going to use steel to span, The inner wall is 4" block on flat 100mm cavity and outer leaf is 100mm edge.

The opes are 5.5m 2.8m and 4.5m

I don't think catnic supply these sort of lengths so im looking at getting RSJ's the inner leave will need to be 8" by 8" to correspond to the block work and the outer leaf will be 4" by 8" is it possible to get these or what is the closest measurement to these?

pete6296

8" by 8" and 8" by 4" are a standard size RSJ where you can source at any steel engineering company. I had a span of 4.5 metres and my engineer told me to use 12" by 12" RSJ so before you buy any, make sure to check size and length of RSJ with your engineer.
Pete

Jollyman

Cheers thanks for that Pete, have the engineer looking at the size at the moment! Anybody know of anyone in the waterford area where i could get them?

250882

Try some lintel crowds, they might be able to give you a thermally broken solution thats more slimline than an RSJ. plus itll be galvanised with mesh to provide a key for the plaster

Jollyman

Have tried them alright and catnic don't provide a lintel that will carry an inner leaf of 215mm block on flat!

Keystone provide a lintel alright that would suit but it is actually more expensive then getting an 8*8 and an 8*4 girder for the same location.

Its easy enough to box around it after and i reckon it will be more structurally sound

250882

Price galvanised on the outer leaf at least. otherwise youll get rust stains down your windows

blindman

Jollyman wrote: »

Its easy enough to box around it after and i reckon it will be more structurally sound

It seems common practice to gripfill plasterboard underneath and box in an airgap at the side (I recently came across one job where someone just skimmed directly underneath a rsj). Give some thought to hanging blinds and curtains, and install some timber for fixing to. You only build once but you'll be trying to attach fittings forever.

Mellor

Jollyman wrote: »

the inner leave will need to be 8" by 8" to correspond to the block work and the outer leaf will be 4" by 8" is it possible to get these or what is the closest measurement to these?

Get what is needed, not blockwork dims. Firstly because it may not be enough, and secondly because steel is expensive, especially in those lengths. If the required RSJ doesn't mot fit in perfectly with blockwork dims, make it up in the wall, not the beam. Do this with concrete bricks, slips or cast pieces (make up to top edge, pad stone below.

Jollyman wrote: »

Have tried them alright and catnic don't provide a lintel that will carry an inner leaf of 215mm block on flat!

I think they do (infact I am sure). It is the inverted T lintel, looks like an RSJ without top flange, 215 block sit vertical on either side of web, with a 215 on flat above. This lintel holds the inner leaf only and the outer leaf is separate, this is better than a combined one for thermal reasons.


Youe opes are huge, is it going to cause major heat loss through windows/doors that big?

Jollyman

Could not agree more with you on the issue of making up the difference with the blocks it is far cheaper, my father is laying the blocks and he would prefer to see them matching heights to make his life easier, and in this case the price variation was very little.

One of the opes is for a double garage door, the others are both in the sitting room and will hopefully be putting in triple glazed windows i don't think the heat loss will be huge!!

8 lengths of steel 8*8 and 8*4 147 meters in total €1410!

Mellor

Triple glazed or not, a 4.5 m window will lose alot of heat. How high is it, about 1.4? Its probably too late now, but it seams oversized to me. I generally work of a ratio of the floor area, maybe the room is big enough.

All that is too late now, but the good news is the steel came in at a decent price. Did you leave a zero out

Jollyman

The room is 47.49M2 there is 2 900mm windows one 2.8m and a 5.5m ope that incorporates a bi-fold door!

No the steel is €1,410!

I should add that it has a vaulted ceiling and will be open to upstairs also!

NovaGSi

Hi Jollyman,

how did your steel work go?

Did your 8 lenghts join to form a ring for the vaulted cieling?

Any pictures?

Cheers,
Mick

Jimmycooker

Jollyman,

Can you tell me how you got on with your bifold doors?

I am building a granny flat and want to put in a 4.5m wide bifold door across the front (the building is 6.5m wide in total with 1m to spare on either side).

Who did you buy your door off? Did you go for a flush or raised (weathered) cill? My plan is to support a bedroom / ensuite in the attic space and have 100mm/100mm/100mm cavity walls.

Any info / lessons learned would be greatly appreciated....