Roof truss upgrade for flooring loft, to allow for storage.?
Question:I am planning to floor my loft, however just now they trusses are out of 4x2s. the span is 8m with a supporting wall in the centre. all internal walls are of brick construction and the presumption that the central wall is supporting is that the roof trusses are joined on top of it. due to the lack of interest in planning permission and building regulations I am unable to check the suitability of the current structure for flooring. so can someone tell me what i would require to do to floor the loft safely, I only intend to use the central 4m of the roof as the outer edges are too low. the floored area will be 5.5m x 4m. i think i need to upgrade to 6x2s however 12@ 8m will be expensive and heavy so is this required or can i possibly get the same results in a different manner, using less materials. i also plan to board the underside of the roof to create a little clean work place. adding insulation as well, as it is cold up there in the winter. thanks in advance
Answers:
The storage aspect isn't really a problem, unless you are going to lug really heavy items up there. Chipboard loft flooring (available at all DIY places) will spread the load across the joists (but be careful about access to the cables for the bedroom lights). It would be better to store things round the edges (nearer to the walls supporting the joists) than in the middle of the joist span.
But your mini-office is a problem. In regulatory terms, it amounts to a "habitable room", which brings in the Building Regulations and all that they involve by way of headroom, access by staircase rather than loft ladder, means of escape in case of fire, window area and, of course, beefing up the joists. However, if you aren't bothered about the Building Regs, you could just lay two or three layers of chipboard across the central structural wall, to form a load-spreading raft for you and the desk or whatever you are putting in your workspace.
But keep an eye open for cracks in your bedroom ceiling below the edges of the raft, caused by your banging around up there. And remember that the regulations aren't there just as a lot of bureaucratic hoops for you to jump through; they do set standards to reduce the risk to your life and limbs.
you are not supposed to deck out a trussed roof ,They are designed to take pressure from roof tiles only ,without the added weight of flooring, you could do damage to the roof
With the ever increasing demand to optimise building land, more and more builders are looking to trussed rafters to provide the solution for additional living areas within the roof space.
A significant proportion of all trussed rafters now produced are RiR trusses which offer up to 65% more living space using a method of construction that has been in common use within the construction industry for some 40 years or so. No outdated or untried methods of construction are needed.
For most purposes 'RiR' trussed rafters can be designed to clear span between the front and rear walls of a dwelling thus avoiding the need for building loadbearing walls and foundations on lower storeys. However, if loadbearing walls exist or can easily be added then they can be used to good effect to provide additional support to the 'RiR' trusses. In this way greater room sizes are possible but to be effective the walls should occur within the centre 20% of the truss span and are most effective when placed near the mid-span of the truss
try this website -www.tra.org.uk/rir.php
At the minute you are actually considering upgrading the size of the CEILING JOIST level not the roof timbers or trusses - this will be very tricky - and ideally should be double checked with a reputable builder.
The horizontal elements of your trusses might touch an internal wall but trusses are designed to work with no such support. You should not remove any of the members from your trusses; they are designed to a cost with minimum safety margines. I appreciate what you are trying to do but keep in mind the fact that you could seriously devalue your house if you get it wrong. When you sell you will have to declare alterations in your sellers pack!
Why not approach some "Attic Conversion" companies and try to poach some of their ideas?
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