Tutor stability
- 1. Building Methods & Construction Technology Stability
- 2. Loading on Parts of a Building Foundation’s constructed as part of the building or structure are termed ‘artificial’ foundation, the ground that they are laid upon is classed as the ‘natural’ foundation.
- 4. The purpose of a foundation is to spread the load, from the structure above, over an adequate bearing area of the subsoil, and to provide a stable, level base on which to build. Although foundations are normally out of sight, the effect of any movement of a foundation is likely to be very noticeable in the structure above. Purpose of a Foundation
- 5. The foundation is sandwiched between the forces from the structure and those from the ground thus subjecting it to compressive forces, so the foundation must be constructed from a material that is strong enough to resist any forces being imposed upon it.
- 6. Loading to the Foundation should always be equal
- 7. When constructing stepped foundations, the construction starts at the lowest level of the site.
- 8. When using Cavity walling below ground • A weak mix concrete is placed in the cavity to resist Lateral thrust from ground push. • Use Ties or not?????
- 9. • A cavity wall consists of two slender walls If a load is exerted to one or both of these slender walls they may buckle or collapse under the load. If the two leaves are tied together they will virtually be as strong as a solid wall and they can support more imposed loadings.
- 10. • A distance of 150mm max from the edge of an opening (BR). • A distance of 225mm max from the edge of an opening (CoP). • Vertically spaced at a maximum of 300mm • 900mm max horizontally (or 750 if cavity is 75mm or more) • 450mm vertically staggered Position of wall ties
- 12. Bonding into Internal walls Indents And Use of expanded metal
- 13. Expansion Joints placed ever 6m
- 14. Expansion Joint Ties and Sleeves
- 15. ATTACHING WALLS TO STRUCTURE (EXTERNAL)
- 16. Opening in Walls Any openings (windows/doors) should be a minimum of 675mm away from any external corner of a building.
- 17. Lintels • The constructional member inserted into a wall to support a load above an opening is called a LINTEL. • The imposed loads create stresses upon or within any lintel, in particular at the top and at the bottom, which may cause cracking and failure. The size, shape and design of a lintel must be such that it can overcome these imposed stresses and loads.
- 21. RSJs USBs must be sat on a concrete padstone (min 150mm) and fixed by means of rag bolts to prevent tilt and slip
- 22. Fixing Truss to Wall • Wall plate – Pan bedded on to ensure level and parallel • Fastened to block-work by Galvanised steel straps screwed to wall and wooden Pan set at a max 1800mm • Help spread load of roof through wall on to foundations
- 23. • Clip used for fixing truss to wall plate • Screw Truss clip
- 24. Anchor Straps • Anchor Strap should fix to at least three trusses and bed into block-work this helps with the roof structure resisting the pull of the gable
- 25. Anchor Straps in Roof construction • These anchor ties should be screwed not nailed
- 26. Galvanised Straps for Fixing
- 27. External Stability • Piers Height should not exceed 8 times its minimum dimension ie: what would be the height of a free standing pier if it measured 400mmx400mm
- 28. The purpose of an attached pier is to :- • Provide the wall with additional strength to counter against lateral pressure. • Accommodate loading and transfer this load to the walling.
- 29. Attached piers • Building Regulations state slender walls should be supported at corners and at intermediate lengths i.e. garages conservatories • Maximum distance between piers = Every 3m