Beam fitting advice

Joolz89 · 27 Jan 2009

Hello,

I am going to remove a partial load bearing arch which segregates my kitchen / dining area.

I have had a SE to do the calculations and the plan which I have now received and I have put my application in for building notice but to keep costs down I am going to fit the wooden support beam myself.

I had a good chat with the SE about supporting the ceiling whilst I do this however what I would like to know is the best method for cutting the recess in the external wall for the beam which has to be 100mm deep.

Any other pointers or advice on this would be appreciated.

Untitled

Joolz89
27 Jan 2009
1

noseall · 27 Jan 2009

we would stitch drill then hammer and cold chisel or bolster it out.

stitch drilling involves drilling several holes on the marked out perimeter plus a few inset holes to weaken the masonry.

you will need to sleeve the beam to deal with any shrinkage.

it pays to have the beam resting in place somewhere below its final location as it can be difficult to thread the beam in-between the acro props.

^woody^ · 27 Jan 2009

That's one chunky beam to be having to duck under.

Did you actually want this in timber and in that position?

Has consideration been given to shrinkage and twisting when the timber starts to dry out in the warm room

I'd also wrap the bearing in polythene or similar to prevent the chance of rot when in the wall

And watch those bits falling down the cavity when you break/drill through

The beam is going to be longer than the room width and so, the hole for the bearing is going to have to be wider (and deeper) than the size of the beam so that it can be inserted at an angle before being placed in its' final position

Joolz89 · 30 Jan 2009

Thanks for the replies and advice fellas it is appreciated.

Never thought about the fact that the mounting recess would have to be bigger due to the length of the beam. On the plans it doesn't have a padstone. If I make the cavity longer than required to get the beam into position what is going to be the best method to bring it up to the required height when fitted?

The beam will only be marginally thicker than the existing top bar of the arch that is fitted at the moment so head clearance won't be a problem. The SE recommended a wooden beam because of the fact at one end is a partition wall and he said it would be a better method due to the issues with supporting the beam at that end.

Also weaving the beam in and out of props could have been amusing so thanks for that tip as well

^woody^ · 30 Jan 2009

There is nothing wrong with sitting a steel beam on a timber post

Timber beams don't require padstones

Push the beam up with another acrow

Joolz89 · 30 Jan 2009

woody thanks again for the reply. Happy about raising the beam to the ceiling however if the cut out is going to be deeper than the beam to allow me to fit it what is the best material / method for packing out the recess under the beam to keep it in place? I read somewhere about using slate.

As too the beam being wood happy with the idea of a wooden beam as it will look nice once finished. However not so keen if it is going to shrink and warp over time thou! How do they manage with normal joists surely it must be properly dried timber.

noseall · 30 Jan 2009

Joolz89 said:
I read somewhere about using slate.

How do they manage with normal joists surely it must be properly dried timber.

once the beam is in its location it can then be squeezed into place with acro props. you can then fill in beneath the beam with regular masonry and mortar.

'normal' joists are sleeved with proprietary shrinkage sleeves.

Joolz89 · 30 Jan 2009

noseall cheers for the info

I take it they are sleeved on the ends of the joist that are seated on the wall and not along the entire length?

noseall · 31 Jan 2009

Joolz89 said:
I take it they are sleeved on the ends of the joist that are seated on the wall and not along the entire length?

correct.

^woody^ · 31 Jan 2009

Joolz89 said:
As too the beam being wood happy with the idea of a wooden beam as it will look nice once finished.

It wont look so nice when its covered in two layers of plasterboard for the necessary fire protection.

A timber section that size has a good chance of splitting and twisting if it is not allowed to aclimatise to the internal air for a few weeks. Even then it may twist or split as it does so.

Joolz89 · 31 Jan 2009

So there is no way I can leave this beam exposed by finishing it other than covering in plasterboard? This was not part of my plan and if that is the case then that is a bit of a dampener. Also the SE never stated it would have to be clad, and even chatted about it be an aesthetic feature once done!

Is there no where I can get a properly treated graded wooden beam custom for the job that is not going to warp and twist and require cladding in plasterboard?

noseall · 31 Jan 2009

fit a steel one then clad it with wood.

^woody^ · 31 Jan 2009

You need to chat to your engineer.

I would suggest that it is part of the engineers job to design a beam in accordance with applicable regulations in mind, which would include one that stays up for a while if there is a fire

I don't think that building control will let a structural exposed beam be unprotected in terms of fire.

You can get chemical treatments, but they are expensive

The problem with a 300 mm deep timber section is that there is a lot of it unrestrained, and so as it starts to dry out and acclimatise it may start to twist and it can split along the grain. Timber is natural, and so what happens is unpredictable.

So whilst the engineer may have considered this purely as a mathematical exercise, and calculated a suitable beam to take a certain load, he does not appear to have considered the other aspects of "the design" in terms of practicality or suitability.

stuart45 · 31 Jan 2009

The beam might be OK with fire regs. If you look at modern post and beam construction houses there is a lot of exposed structural timber.
A thick timber beam is said to perform better than steel in a fire which deforms quickly in the heat.

Joolz89 · 31 Jan 2009

Once again thanks for the replies and advice. Pleased that this is coming out before I start anything, not so pleased that the SE didn't mention any of this. Timber was his recommendation in the first place, not my request!

I have now received the acknowledgement from the building control on the plans and application so on Monday I am going to phone them for a chat, and after this another phone call to my SE as required depending on what the BCO says.

If the plans are deemed as unsuitable by the BC where do I stand with my SE as on the plans its states they meet building regs and are good for submission? If another design has to be done i.e. steel beam with calculations am I going to end up paying again?

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Beam fitting advice

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