How To Build A Dormer Window Uk

Dormer Construction
Building The Structure

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For any loft conversion project the construction of the dormer and its design phase is vital in ensuring that the available space is maximised to ensure adequate headroom is bachelor.

For the purposes of this article lets expect at a typical flat roofed box dormer though in that location other options and designs open up to you lot.

The Process in a Nutshell

Building the structure usually follows a well worn path with the starting time phase being for the builders to cut into the existing roof and removing the tiles and battens.

The structure itself is so put together with a timber frame that is then dropped into the hole. The usual system for building the framing is to use vertical studs betwixt a timber caput beam and base plate for maximum strength.

Once the construction is in place the windows will be installed. The dormers roof is and so built and put in place before the whole construction is clad with cloth such every bit tile, boarding or Upvc.

The Build

To a layman framing dormers looks very complicated and involved.

Fortunately thought about joiners or carpenters volition have petty trouble in putting together the timber studwork.

And at that place are good reasons why dormers are normally synthetic from (soft) forest.

The first and probably nearly important point in using softwood for dormer construction is that the finished construction is light and also very strong.

They can also be constructed very quickly. Once the existing roof tiles and battens have been removed to leave a gap in the roof it is fourth dimension to brainstorm the dormer construction.

The first step in really putting the construction together is to build the base plate or sole plate as information technology is often called.

The base plate is the length of timber to which the bottom of the vertical studs are fixed.

The base plate will then be fitted to a steel beam or or sometimes directly to the joists of the new flooring. Information technology could also exist possibly fitted to the wall if edifice up from the main wall. It is important that structural calculations are taken into consideration here because in that location may be a minimum forcefulness requirement for the studs if the new structure is load bearing.

The studs themselves volition be made from 4x2 (sometimes larger) timber with no more than than a 350mm gap between each.

Equal spacing is desirable but not always practical depending on the size of loft windows being used.

In a dormer it is the front end of the structure volition has to be strongest and volition take on the primary burden of load begetting.

To achieve this a timber head beam is used. This beam will accept the loading from the front of the dormers roof and then its specifications will have previously existence noted in the plans submitted to the councils building control officers.

The axle runs horizontally across the summit of the vertical studs and will support the loading from the dormers apartment roof.

The built up sides of the dormer structure are called 'cheeks'.

The sides, or cheeks, of the structure are not normally load begetting so the dormer framing studs are oftentimes fixed to the existing rafters in the roof.

Although not always needed it is e'er all-time practise to install at least ane row of noggins throughout the dormer framing.

The noggins won't add together significantly to the weight of the dormer and merely will increment its strength.

One time the timber structure is in place the sheathing needs to be added along with breather membrane before the new construction if finished off with cladding.

The Windows

A windowless dormer is very uncommon. In fact why on globe anyone would build without windows is quite across me though to my surprise I have come across such a thing.

Assuming that you want a view, fresh air and natural light in your loft conversion then a suitably sized opening needs to be left in the timber framework though remember that extra vertical studs will exist needed to support the window.

Weather Proofing

The first step in protecting the dormer from the vagaries of the British conditions is to clad the framework with timber capsule.

Plywood sheeting is normally used for this and its purpose is to provide a backing for the insulation also as keeping out the air current and pelting.

The external facing side of the sheathing then needs to be covered with overlapping sheets of breather membrane. Every bit its proper name suggests the main function of the membrane is to permit condensation escape.

The final footstep in dormer construction is to fix battens to the sheathing onto which the terminal covering of tiles or atomic number 82 sail is fixed to complete the cladding.

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