advice needed for rsj/catnic on garage wall please!

[1crb1]

Hi to everyone, new to the forum, hope to be using it alot now as ive got a new house to renovate with the family!

My first port of call is this, our double garage is all lovely and wide enough. Unfortunately the length isnt. Now attached to the gable wall end is a worskshop thats been fitted after at some point. It shares the wall of the garage, and the other three walls are prefab and have been rendered.

I want to make an opening so the nose of our car can fit. My knowledge of this sort of work is limited at best, ive been scouring the net for info but need to ask some questions.

I have a builder friend who has agreed to help but i want your advice.
I would like an opening of 3 metres. The wall is not supporting the wall although there are a few joins to the blocks as you can see in the pictures below.
Now the wall appears to be double skinned breeze block, with a thickness of 200mm.
Can you clarify what is needed here:
1.So i would need to a 3300mm support- what would be required? a normal steel, catnic of some kind etc etc.
2. Following on, does the support have to be 200mm wide to support the 200mm of wall or can it be narrower.
3. Steels with a width of 200mm are called columms but the heigth seems to go silly big for what ( i think) we need?
4. Should i fit padstones, if so what sort of size?

So could anyone help as to what is needed here. Its not taking alot of weigth, 6-7 courses and a little bit of roof?

Here is a pic of the wall just for measurements, top right is the block dimensions.

I thank you in advance for your time and my ramblings!

Cheers Chris[/img]

 

[1crb1]

Forgot to add the garage is free standing from the house! Not sure that matters!

 

[masona]

Can you do another drawing of the top view elevation including your house, is the front of the garage in line with the house etc? The workshop, is this on the other side of the wall?

 

[1crb1]

Sorry Should have explained better. The garage is independent of the house. One end is the double up and over, the other is the wall I would like to open up. Following on from that wall is the workshop tagged on the back.

 

[tony1851]

Two 7"x4" steel beams ('UB's) side-by-side would be fine on that span and with that loading.

 

[1crb1]

Tony thanks for your reply. Yeah theres not alot of lad there is their. When using two steels, do the they need to be bolted together? Cheers again
Chris

 

[tony1851]

If you can bolt them together (say in 3 places through the webs with 1/2" threaded bar) that would help them to work togther and would be even better.

 

[1crb1]

Great thanks again. One last thing, would a single column be better for cost etc or just go for two single UB's?

 

[tony1851]

Steel is usually sold by weight.
The smallest single beam would be 8x8x47, which would be around150kg.
The 7x4s would be about 63kg each. The single beam might be quicker/easier in the long run - also no concerns about bolting together.
See if you can get second-hand; both sizes are fairly common.

 

[1crb1]

Many thanks for your time! Defo last question, any rough Idea of the size of the padstones I should use?
Cheers

 

[tony1851]

padstones 215 long, 140/150 high and 100 wide would be fine.