BS 5997 cost

[brianivor]

I am planning to put a single door through an internal loadbearing wall in my house and need to calculate the size of lintel required to satisfy the Building Inspector.

I was referred to BS 5977 to do this but when I Googled this document the web site wanted £90 for a copy!

Is this the going rate? it certainly doesn't encourage one to do the job properly but take a gamble with the size, maybe putting in a lintel much larger than required - is there cheaper way of getting hold of a copy?

 

[gday2uk]

Just ask the BI what they want. It's only a door so I would imagine a lintel with 9" bearings each side would suffice?

 

[Static]

Most large librarys have copies of all more common british standards.. and can be viewed for free..

But if its just a little internal lintel, most lintel manufacturers can spec one for you if you do a little dog work and measure up spans etc.. unless your putting in some silly sized tripple folding door or there is a large point load on the area..

 

[brianivor]

Thanks for your replies - I hadn't thought about the library.
Yes its just a single doorway in a coventional house with a nine inch solid wall
so it should be straightforward - I'm just off to the library.
Thanks again.

 

[Static]

Hold on.. actually went and looked at BS5997 and it was withdrawn in 1998 and replaced by the BSI Construction Standards Manual. Also it was all about building services (gas/electric etc) .. you sure you have the right number?

edit: ah perhaps you ment 5977.. either way i think your wasting your time and should just contact your chosen manufacturer.. BS's are sometimes a little complex to follow..

 

[themiddleagedun]

Just use 2 140x100 concrete lintels 1200mm long. Job done.

 

[brianivor]

I finally got through to a copy of BS5977 at the library and althought it taught me a few things, it didn't actually decribe the weight calculation process - so not a good result there.

I guess I could have asked a building inspector, but as I was planning to do the job myself, I wanted to create a good impression straight off by demonstrating that I fully understood what I was doing.

Thats how I lke to work and I would never undertake a DIY project without all the information required.

Based on what I have gleaned from the library, i.e. the load triangle and the interaction zone, I would think that the (2) x 1400 x 100 sized lintels seem a bit excessive and that (2) x 75 x 100 lintels would have been adequate but thats why I raised the question in the first place and I would rather overestimate the final size than put my family at risk.

But I don't like to feel I am cutting corners, hence I would still really like to do the calculation myself and get the satisfaction that I am totally responsible for my actions.

 

[^woody^]

You are looking into this way too much and making life hard for yourself

This type of work has been done thousands of times before and the BCO will know that a certain lintel will be fine, and will not be wanting any calculations if that certain type of lintel is used. And for a single internal door, that certain lintel is a 65mm deep concrete one, or a box lintel from one of the various manufacturers.

Obviously if you ave a massive RSJ holding the roof up and this is sitting right on this new lintel, then things will be different.

Don't worry about making a good impression with the BCO by getting all technical and giving him reams of paper calculations - you will be doing the opposite, and he wont be expecting it

 

[brianivor]

Thanks, Woody,

The light of reason!

I will go with your suggestion of sizing and leave it to the building inspector to raise any issues.

Thanks also to all who took the trouble to comment on my concerns.

 

[^woody^]

If you have not already done so, find out who your inspector is and give him a ring on the pretence of how soon he will be available for any inspection or what he needs to look at etc, and then just casually say "OK thanks, there should not be any problem with me using a normal 65mm concrete lintel for my door opening is there? The doorway is only [800mm] wide"

I can't see any problem, but at worst use 2 x 65mm lintels one bedded on top of the other, as this is easier than lifting a 140mm deep one and cheaper than a steel box lintel

 

[alittlerespect]

Hi

If not already done - you should go for a standard sized pre-cast concrete lintel - 220mm (w) - aprox. thickness of wall x 65mm (h) - aprox height of one brick - so it matches in with the brick courses x length of opening + 200mm for minimum 100mm bedding at either end.

220mm is recommended because of the load characterists of the solid wall, but some people do approve 2 x 100mm as they are easier/safer to handle, but over the span you are going 220mm is not going to be that difficult to handle.

You may want to put one pin through the wall around the centre point of the opening (above the top line of the lintel to provide some temporary support, a 'jack all prop' may do the job (seen them but never had cause to use them.) Basically, install the jack all prop, cut out the opening for the lintel, install the lintel leave for 24 hours to allow the mortar to set, take out the jack all prop, and then gently trim out your door opening, install door lining, make good to disturbed areas, finally add architrave, door and door stops, and decorate - job done!
I say gently, as I have known people take to a wall as if they have a sledge hammer in their hands, and if you follow such antics you could end up rupturing the wall.

Some experienced people don't use a pin, but you would need to know what type of mortar you are dealing with to know how well the mortar is bonded to the brick/blockwork. For that reason not a recommended course of action for the DIYer!

Regards