why can't you cut a steel lintel anyway?

Discussion in 'Builders' Talk' started by clueless jon, Aug 3, 2008.

  1. clueless jon

    clueless jon New Member

    I have a box lintel which is about 60cm longer than i need it. All the literature says you shouldn't cut lintels because of structural integrity etc. but i don't understand why - as long as you've got 150 bearings each end why does it matter what happens to the extra bit? are the suppliers just being paranoid?
     
  2. Major Mal Funxion

    Major Mal Funxion New Member

    That does sound a lot of tosh CJ, If every opening was tailor made to suit the lintel manufacturer, where would we be?
     
  3. Mr GrimNasty

    Mr GrimNasty Active Member

    Possibly to prevent future corrosion in the case of galvinised lintels.
     
  4. Cornish Crofter

    Cornish Crofter Active Member

    I enquired after a damaged Catnic lintel at my local Travis Perkins. They quite often dispose of damaged goods, and I have been given a few bits in the past.

    This particular lintel was damaged at one end, affecting about 12 inches of it's overall length.

    The manager told me that they intended to cut off the damaged end and sell it as a shorter lintel. Made sense to me. That's exactly what I would have done.

    I suspect that the manufacturer is basically covering himself. After all how does he know how the lintel is to be cut and how much heat is to be generated.

    If a torch is used for the job then the heat affected zone could create real structural integrity problems.
     
  5. Mr GrimNasty

    Mr GrimNasty Active Member

    The no cutting advice is specific to lintel codes starting 'CG' - I suspect the G stands for galvanized.
     
  6. gadget man

    gadget man Screwfix Select

    I've cut them before and they were OK'd by the BCO!
     
  7. Cornish Crofter

    Cornish Crofter Active Member

    The no cutting advice is specific to lintel codes
    starting 'CG' - I suspect the G stands for galvanized.

    Makes sense
     
  8. wardoss

    wardoss New Member

    Some of the heavy duty Catnic Lintels cannot be cut as they have reinforced end which provide the additional strength.
     
  9. Major Mal Funxion

    Major Mal Funxion New Member

    History shows us guys , that masonry, if built by a tradesman will pretty much hold it self once it's cured or gone off. All the lintel does is give peace of mind. More often than not, we have to prop lintels, until they go off the next day or so...and you'd be amazed at how many punters panic, when they see you do this.

    We always have to reassure them it's just to stop deflection until it has gone off, after that, the masonry will do the rest. In the days before lintels, you will always see a relief arch about 4 courses above an opening. This was more common on brickwork that was n't seen, and obviously when it was seen, the more traditional decorative arch was used directly above the opening. So the lintel manufacturers are more likely the ones spreading such tosh.

    On my own house , which was built in the 70's, there is no lintel over any of the windows on the outer leaf, and one is 2.7m wide. what they did was ( and i don't advise it ) is roll exmet over the span for the 5 or 6 courses above the opening, and when i took the patio window out recently, it wasn't exactly in rush to go any where!
     
  10. wardoss

    wardoss New Member

    HJ is right, all lintels do in general is support the triangle of brickwork above the opening during construction. Unless there is a point load lintels could easily be removed after brickwork has gone off with no affect on the structural intergrity.

    As a side note I have visited the Catnic factory and some of the lintels are still put together by hand!!!
     
  11. Mr GrimNasty

    Mr GrimNasty Active Member

    The problem with self-supporting brickwork over openings is that once any crack appears a single brick can drop - once that happens it is like removing a keystone with further rapid deterioration or at worse partial collapse - a lintel stops that first brick slipping even if a crack appears and the integrity is maintained whatever.
     
  12. joinerjohn

    joinerjohn New Member

    Wish I had a pound for every brick that's fell out when removing old windows from properties having double glazing in. I used to work for a joinery firm years ago and they had a council contract replacing old timber window frames with new hardwood framed d/g ones. The amount of properties I worked on that had a brick soldier course laid directly on top of the wood frame was unbelievable. These were in properties built in the main in the late forties. The brickies had a field day replacing the brickwork that fell out when we removed the old windows.
     
  13. clueless jon

    clueless jon New Member

    Well i spoke to catnic and it seems Colt P is right - it is because of corrosion, and you can cut it as long as you paint the cut end with something to seal it. My floor is only one course above the lintel, so i don't think it will stay up after the lintel has rusted away . how many mm a year would it corrode along the length of the lintel anyway? not many i'll bet.
     
  14. Major Mal Funxion

    Major Mal Funxion New Member

    Precisely CJ...They have to say something on those lines i guess to cover thems derriere
     

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