Lintels

[deuce22]

Hi.

I am just about to start constructing the walls of a bungalow and need quite a few lintels.

I'm looking for some info on what I should be fitting.

The two brands I'm looking at are IG and Catnic.

As the building regs changed in October I'd like to know which ones I should be getting.

When I used to fit the ones for a 100mm cavity the insulated part was only 88mm wide, so it didn't close the whole cavity.

I've now had to build the walls with a 110mm cavity, but don't know if I can still get away with the lintels for a 100mm.

I need to know the correct specs as I'm trying to compare between the 2.

Thanks.

 

[^woody^]

You need to look at the manufacturers specifications and select the type for your cavity width

Typically, there is a range 40-75mm and 75-100mm so you will not be able to use either of these for a 110mm cavity

If there are no cavity lintels for 110mm cavities, then you will need two lintels - one for each leaf

 

[leew2]

Catnic have a search tool you can use to find suitable lintels, just enter your wall/cavity sizes and it will show which lintels will fit. http://www.catnic.com/productsearch.aspx

 

[deuce22]

Thanks both.

So it doesn't really have anything to do with the width of insulation, it's more to do with the structure of the lintel?

Someone told me to just use a 100mm lintel as there's not much difference between the two in regards to the loads it can handle.

Cheers.

 

[hotrod]

IG do a 95-110mm cavity lintel range:-

http://igltd.co.uk/standards/95-110cavity.htm

Ignore the price list. Merchants will discount that % for you. I've always found IG cheaper than Catnic for comparable products. Depends what your local merchant stocks, the quantity you require, and how much % discount off list you can negotiate obviously.

hth

 

[theoldun]

The correct lintel sizes for IG are 50-70, 70-95, 95-110. Catnic are 50-65, 70-85, and 90-105
You want the 95-110 I.G. Open Back Standard duty L1/S100 if you are running face work over the openings.
If no face work over opening and soffit is laid on brickwork at head of frame, then use IG HD Box 200.
oldun

 

[deuce22]

Cheers guy's.

I've just spoke to the structural engineer that I use (and is also working on this project for me as and architect) and he said that I can use the standard 100mm lintel.

There is hardly any difference in the structural integrity between the two.

The difference in price between the 100/110mm catnic is £56 and £104.

I realise that safety is the most important consideration, but as the engineer is happy with it, I'm not going to pay almost double the price for nothing.

If there was a genuine reason to have to buy the wider lintel then I would, but even the rep from Catnic said it was a rip off due to the new regs stating that you now have to have a 110mm cavity.

Cheers.

 

[^woody^]

There will be more of a tendency for brickwork to tip on the lintel as there will be a greater overhang of the walls.

The lintel may be OK in terms of pure load bearing or if there was built up masonry above, but as it is a bungalow with little walling above the lintel then I'd be sure that the lintel is actually "suitable" rather than "adequate"

 

[deuce22]

Hi woody.

So are you agreeing with the SE that a 100mm is sufficient to use.

I like confirming most things on here as there seems to be a lot more knowledge from people practically doing it day in day out rather than just knowing the theory behind it.

We are only 6 weeks into the project and a few issues have arisen between myself, the BCO and Architect/SE that I would do differently next time.

I just don't trust them 100% to do exactly as they say.

Cheers.

 

[theoldun]

You want the 95-110 I.G. Open Back Standard duty L1/S100

oldun

Both hotrod and ourselves told you that you require L1/S100 and not L1/S110.
L1/S110 is a different animal altogether. It is made for a cavity of 110-125, and is wider and higher and normally costs 30% more than a 100
There are no new regs stating that you now have to have a 110mm cavity. The IG rep wants going through the hole in the hedge.
We do it all day every day, and know just a little bit about what we are talking about. A L1/S100 is made to take a 100mm block inner skin and there will be no tendancy what so ever for the block to tip over. Your SE is correct.
oldun

 

[deuce22]

Thanks oldun.

I've finally got it.

Whats confusing me is the thickness of the insulation in the lintel. The L1/S100 has an 88mm wide thickness and the L1/S110 has 108mm.

I assumed that it was the width of the insulation that was the deciding factor.

I noticed that you said that the new regs does not state that the cavity has now got to be 110mm.

I'm now wondering why the BCO told me that.

Is it worth me buying a copy of the 2011 building regs book. Will this sort of info be in it.

Cheers.

 

[theoldun]

We set our cavities to 105mm to give tolerance for insulation, but sometimes depending on whose insulation you use, this is a bit tight.
110mm is acceptable..

Building Regs are on line. Google Approved Documents and take your fill.
Will take you about 14 days of solid reading.
oldun