How is a loft converion done?

[86c]

I'm thinking about a loft conversion in the near future and i'm curious on how its done. I know that the roof will need insulation then plaster boarding but what about the floor?

My house is a 2 bed 1900 mid terrace. As the 2nd bedroom has a stud wall separating the room from the landing and a load baring wall by the staircase, I'm thinking removing part of the partition for a stair case to the loft.

Doing this will mean cutting some of the joists in the loft this will mean part of the floor is unsupported so what will need to be done to make the floor safe? I am probably going to get a builder to do the floor but its nice to know these things

oh while I'm here save making another topic, I have a bouncy living room floor, I briefly read somewhere that sistering the joists can help. How is the sister joists attached to the original joists and what dimensions of wood would I need?

 

[Static]

First of all go into your garden and look at your neighbours properties and see if any of them have dormer windows of roof sky lights that would indicate they have been converted.. if so then there is a good chance you can also convert yours..

Actually nitty gritty really depends on existing roof structure, load bearing wall locations below, your plans for conversion and your budget..

 

[86c]

None of the houses I can see have skylights or domers. But before we brought this property we looked at several others around the area one had a conversion done a few streets from here, so it can be done.

It was a good size room only thing was that it had a ladder going up which we didt like. I have a staircase in the middle of the two rooms so the wall separating the 2nd room and the stairs has to be load bearing as the joists run from the front to the back of the house.

 

[Static]

Well the fact the only one you have seen is a non building regs conversion probably means that something is stopping others doing the conversion.. could be alot of things from headroom to roof construction, sometimes planning restrictions scupper plans..

Anyways normal process of your run of the mill purlined terrace would be dormer on the back with stud walls supporting the purlins built off steels going into the party walls.. then new joists between the two new steels for the new floor.. then hope you can squeeze and space saver stairs in and fire doors etc.. architect, building control, builder, new builder when first turns out to be a dud, job done, snagging, maybe even pay final builder bill..

 

[freddiemercurystwin]

Typically a steel beam is fitted just above the existing ceiling joists spanning from gable to gable on each side of the roof (you need a structural engineer for this bit). New floor joists are installed spanning between the steels. A structural timber stud wall is built up off the steels that support the purlins/rafters. Provided you have plasterboard and fit some mineral wool insulation in the floor that will probably satisfy Building Control. There is a reduction in existing floor to ridge height of around 300mm with the addition of a new floor and insulation above so first thing is to check what available head height you have. Sometimes a dormer is required

Rigid insulation is fitted between and under the rafters.

A permanent stair needs to be fitted in order to make it a legal habitable space. this can be a traditional stair or a 'spacesaver' stair. Minimum width for the stair is 600mm. This can often be the most tricky thing to do to fit the stair in, usually partitions need a little bit of modification.

You need a door at the top or bottom of the stair to separate the loft from the rest of the house. Most of the other doors in the house opening onto the stairs will need to be upgraded to be fire resisting but they will not need closers. You will obviously need some rooflights for light and ventilation.

Typical sections look like this

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• 14 Apr 2010
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• freddiemercurystwin
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• freddiemercurystwin
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You'll need to familiarise yourself with the relevant Planning laws and Building Regs which although simple for a lofty they may will not be so easy if you have little knowledge.
http://www.planningportal.gov.uk/permission/commonprojects/loftconversion/

 

[86c]

Thank you I shall have a look at that link, a loft conversion is looking to be not so simple after all

 

[petercmfjohn]

My advice is to consult a local builders or loft conversion companies

 

[freddiemercurystwin]

My advice is to consult a local builders or loft conversion companies

Wow! Great first post!

 

[geraint]

My advice is to consult a local builders or loft conversion companies

Wow! Great first post!

should that not read .... greats firsts posts....