Most people who are thinking of extending their house by incorporating a new loft conversion just leave the details to the architect or builder and only start thinking about what exactly has to be done when the bills start rolling in. The biggest costs involved in any sort of house extension involve removing or building important floors, walls or roofs. All three might be involved in loft conversions, but a new floor is certainly a must in any case. The article below explores the issues involved in building a new, solid foundation for the exciting new room above your house.
Any new floor that is going to be constructed to support the new loft needs to be supported sufficiently. The architect will be able to make a decision on what is best in this situation or they might bring a structural engineer in to have a look and give some advice about the strengthening method required.
Usually it is done by installing structural beams under the floor, which are normally made of steel. Occasionally, it is judged that the loft walls are strong enough to support the floor anyway. The engineer might also suggest other strengthening modifications. These might include building a separate wall whose sole function is to help give support to the roof by tying it into the floor. This wall is called a “purlin” wall.
Sometimes, the new floor might require removing the supporting joists to be removed. To compensate, the new floor has to be structurally tied in to the slopes of the roof or the outer walls to give it more support as well as new joists being built to replace the ones that have been removed.
The Building Regulations will determine what extra requirements are necessary. The new floor will have to be designed in such a way that it is fire and sound resistant enough to meet new standard and cope with the fact that the loft is likely to become a place for people to use on a regular basis. The fire resistance standards require that the materials that the floor is made from are fire retardant enough to resist a fire starting for a minimum of half an hour.
The requirement for resistance to dampness and moisture will depend on plumbing being installed aloft. If there is a new bathroom or toilet going to go in the space in the loft, then the floor will have to be moisture resistant enough to meet the Building Regulations standards.
The other requirement that affects the way the floor is designed will be access. The old opening to the loft that existed before hand may have simply involved sliding a hatch across and using a ladder of some sort. The new loft will need a set of stairs for access and this will probably mean constructing a strongly built access area in the floor to take the top part of the staircase. The new staircase will also mean that some sort of landing, however small is required both at the bottom of the stairs and at the top, in the loft. Inevitably some space is lost to the landing, but this should be normally be made up for by the expanded loft space.