Loft Beam Removal

[Walmsley]

Could anybody please provide some advice.

Our house was built in the 1960s, it is a semi detached and of concrete construction.

There is a horizontal beam in the loft (see pics) which we would like to remove to create extra storage in the loft.

Untitled

• Walmsley
• 24 Mar 2012
• 2

Untitled

• Walmsley
• 24 Mar 2012
• 2

Untitled

• Walmsley
• 24 Mar 2012
• 2

Untitled

• Walmsley
• 24 Mar 2012
• 2

Untitled

• Walmsley
• 24 Mar 2012
• 2

The beam is secured by a bolt to the rafters on either side of the roof.

Instead of removing the beam would it be possible to move the beam higher up towards the ridge? Maybe introducing a a couple of new beams instead one just one?

Would this be possible.

We are looking for a builder though we would like some idea of what they tell is correct?

Many Thanks

 

[HERTS P&D]

Why is there insulation between the rafters?

Andy

 

[Walmsley]

We have just recently moved into the property and when going in the loft this is how we found it, we are in process of removing it from the rafter as there are a few holes in the felt.

It looks like its been placed there to cover the holes.

Thanks

 

[tony1851]

Difficult to say without seeing the whole of the roof, but could it be a device for giving some intermediate support to the purlin? This might explain why the bridging piece is bolted between 2 closely-spaced rafters.

How is the purlin supported at the other end, is there any intermediate support (eg from a wall below) and what is its approximate span.
Published tables give guidance for the maximum span of purlins dependent on the cross-section size of the timber. If your unsupported span exceeds these, its possible that the bridging piece is intended to give some support.
Maybe somene else could come up with suggestions?

 

[catlad]

It is there to support the purlin, I have seen this were the purlin is undersized say were normally 9x3" it is 9x2" something like that anyway if you take it out your roof will probably start sagging in the middle.

 

[Click4]

no expert, so dont take my advice without more knowledgeable oppinions.

but id guess one way to remove the support would be to double up the purlings to increase their thickness by bolting and laminating another piece of timber to it.

 

[noseall]

Looks like a purlin support collar, allowing a smaller sized purlin to be used. Without the additional support it may have meant using expensive (at the time) steel as a purlin or greater sized rafters.

Is there another one at t'uther end?

 

[Walmsley]

This is the only beam in the loft goes from one side of the rafters as per picture to the other side. No other supports within the loft space. just this beam. there isnt either another beam supporting the perlin on the outer side which is why im wondering if its needed.

Thanks

 

[tony1851]

What is the other end of this offending beam fixed to? Is there a corresponding purlin on the other side?
Although you say there is no intermediate support to this purlin, you don't say what total length (span) is. This is important because it can give a clue as to whether or not it is overspanned, and hence whether or not this awkward beam is providing support to the purlin.

 

[Walmsley]

The other end of the offending beam is exactly the same bolted into the rafters as per picture.

Its a semi detached house and there are three purlins two of these come out of the seperating wall and the other joins to these two.

The length of the purlins are 4.1mtr and the size of the purlin is 20cm x 5 cm.

There are upright struts from the floor to the purlin and also into the rafters even though you cant see them in the picture but these are only on the purlins from the divided wall.


On the purlin located on the outer wall of the house there are no supports by means of struts or beams.

Many Thanks

 

[tony1851]

Looking at the published span/load tables for roof timbers, the maximum span for a 50 x 200 purlin is given as 2.52m, for a roof of 'average' slope and 'average' weight of roof tiles (even with a higher-grade timber, it is only 2.63m).
This suggests that at 4.1m, this purlin would be well-overspanned in the absence of the awkward beam and that it is providing support. Realistically, the only way you could get rid of this cross- beam is by beefing up the existing purlin, eg by bolting a 10 x 2 timber on to the side. This extra beam would not have to go right into the party wall, nor join to the angled hip at the other end, as long as it was firmly bolted for most of its length. A 3.6m length would probably be OK. How you would get it into the roof is another matter.
The struts you mention are probably ceiling hangers, intended to support the ceiling joists, rather than giving support to the roof itself.