I want to board my loft and use it for storage and as its quite a big area store some of my electrical tools up there (rather than risk them in the shed). As I may be walking around up there and storing a lot of stuff the electrician who has just fitted a light up there advised I could get the joists strengthened before I put the flooring down (I’m planning to use 18mm t&g). If I do this do I need to contact building regulations, its not going to be an habitable room, just a storage room that I may utilise now and again as a base to work from for any home improvements, also would I need to inform my buildings insurance to tell them I am strengthening the joists? Thanks

  • Peter Eade

    Hi Warren,

    Most ceiling joists are 50X100mm (4”X2”) and generally run the shortest span, usually from front to rear. The joists are supported by the walls below which form the bedrooms. There is normally one or two binders crossing the joists, these take the loading of struts which support the purlins/rafters. For normal loft storage just boarding over the joists is okay but if you anticipate a higher loading then additional joists would be a good idea. The new timbers would need to be placed at the side of the existing joists so that they too will be supported by the wall plates at each end and the bedroom walls below. You will not get these new joists into the roof in one length so make sure they cross over immediately above a load bearing bedroom wall. Without knowing the dimensions of your roof it’s not possible to advise what size timbers you would require. As you are not intending to make the roof space into a habitable room it’s unlikely the building inspector would want to know. One last thing, bear in mind all of the existing timbers in the roof are structural and are there for a purpose and should not be altered.

  • warren hayes

    Thanks for your reply Peter, does each new timber have to run the full width of the house, from front to rear or is it ok if they are just over the area in the middle of the loft that I am planning to board so long as each new timber is supported by a bedroom wall below?

  • Peter Eade

    The important bit is to ensure the new timber joists are supported by the first floor walls at each end, the joists do not necessarily have to span the full width of the house.

  • warren hayes

    Thank you for the info.

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