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Support first floor joists... concrete block wall against old stone wall or RSJ

  • 02-11-2017 8:45pm
    #1
    top_dog
    Registered Users Posts: 81 ✭✭


    Hi, I'm looking for some advice on a construction query. I would be delighted to get any advice on below. Thanks in advance.

    I have an old stone two-storey house which I am extending to the rear. In order to support the first floor joists the builder wants to build a wall against the old stone wall of the house.
    The old stone wall used to be the external wall. With the extension it will become internal wall.

    I don't like the idea of the concrete wall going up against the stone wall. There will be a gap between both.
    I would of thought it would be better to have two piers and an RSJ supporting joists.

    I would like to strip the concrete from old stone wall and lime plaster. Then use RSJ to support joists. Any ideas on which is best?


Comments

  • #2
    BryanF
    Moderators, Home & Garden Moderators Posts: 10,141 Mod ✭✭✭✭BryanF


    Your structural engineer will advise.


  • #3
    top_dog
    Registered Users Posts: 81 ✭✭top_dog


    BryanF wrote: »
    Your structural engineer will advise.

    Builder was talking to Structural engineer.

    I was looking for advice on having a a concrete wall being built up alongside an stone wall. What issues will that bring. I'd be concerned about dampness and condensation.


  • #4
    sydthebeat
    Subscribers Posts: 41,787 ✭✭✭✭sydthebeat


    top_dog wrote: »
    Builder was talking to Structural engineer.

    I was looking for advice on having a a concrete wall being built up alongside an stone wall. What issues will that bring. I'd be concerned about dampness and condensation.

    any new construction built up against a single leaf stone wall will cause issues.

    you need a professional who will look each factor both individually and holistically.

    its hard for use to comment without knowing the existing design, proposed design of the extension, the direction of joists etc


  • #5
    Mellor
    Registered Users, Registered Users 2 Posts: 39,565 ✭✭✭✭Mellor


    top_dog wrote: »
    I would of thought it would be better to have two piers and an RSJ supporting joists.

    I would like to strip the concrete from old stone wall and lime plaster. Then use RSJ to support joists. Any ideas on which is best?
    If you don't build a wall, where are the piers?

    The question this really boils down to is "What supports the RSJ?"


  • #6
    top_dog
    Registered Users Posts: 81 ✭✭top_dog


    Mellor wrote: »
    If you don't build a wall, where are the piers?

    The question this really boils down to is "What supports the RSJ?"

    There is going to be an RSJ going 3/4 the span of the what was the old back wall of the house. The RSJ is required because the old wall of the back house was taken down 3/4 of the way to create an opening to living room. There will be piers to support the RSJ. The piers won't be going up against the old stone wall. They will be at the end of internal room walls which run perpendicular to the RSJ. See attached which may help explain a little better... hopefully


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  • #7
    Mellor
    Registered Users, Registered Users 2 Posts: 39,565 ✭✭✭✭Mellor


    top_dog wrote: »
    There is going to be an RSJ going 3/4 the span of the what was the old back wall of the house. The RSJ is required because the old wall of the back house was taken down 3/4 of the way to create an opening to living room. There will be piers to support the RSJ. The piers won't be going up against the old stone wall. They will be at the end of internal room walls which run perpendicular to the RSJ. See attached which may help explain a little better... hopefully

    You'll probably have to put in columns rather an piers if the perpendicular walls are already built.


  • #8
    top_dog
    Registered Users Posts: 81 ✭✭top_dog


    Thanks Mellor but I was looking to know more about the block wall and if there will be any issue with it going up against a stone wall?


  • #9
    Mellor
    Registered Users, Registered Users 2 Posts: 39,565 ✭✭✭✭Mellor


    top_dog wrote: »
    Thanks Mellor but I was looking to know more about the block wall and if there will be any issue with it going up against a stone wall?
    It's not a good detail imo. Risking damp issues. Creates tricky junctions/details. And it's completely unnecessary. The new wall serves no purpose. I'd delete it tbh.


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