# Attic Conversion - Insulating between and over rafters



## buyingabroad (4 Dec 2012)

Hi all,

We have a hip (pyramid) shape roof. Am planning an attic conversion diy style. 

Rafters are 4 inches in depth. Roof space is 9m x 9m. Purlins on each of the 4 sides with vertical supports (4ft) so lots of open space.

Should I be concerned with the weight of the insulation (50mm between and 50+12.5 insulated plasterboard attached to rafters) on the rafters/roof? I presume 100mm kingspan would be sufficient.

Also, is there any handy diy guide out in the market place for doing this type of work?

Many thanks in advance,

BAB


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## Tired Paul (4 Dec 2012)

Hi buyingabroad,

Sorry I have no info for you regarding your query but I'm intrested in where you are putting you access stairs - we have a hip roof too. we've been told countless times that we can't get stairs to fit over our existing stirs and still have proper head height with the new access point to the attic.


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## Leo (5 Dec 2012)

You need to be concerned about the weight of the proposed flooring and contents of the converted space. The existing roof structures won't have been designed to hold this. Taking a DIY approach is dangerous unless you really know what you're doing, but based on the question, I fear you don't.


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## buyingabroad (5 Dec 2012)

Leo said:


> You need to be concerned about the weight of the proposed flooring and contents of the converted space. The existing roof structures won't have been designed to hold this. Taking a DIY approach is dangerous unless you really know what you're doing, but based on the question, I fear you don't.


 
Questions relates to the roof structure, not flooring. I know enough to ask the question 

Thanks for the reply.


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## picorette (5 Dec 2012)

You ask, will the existing roof 4" rafters support 100mm of insulation plus plasterboard?

Most likely they will, depending on the fixing, but it would be no harm to check with whoever who is advising you on upgrading the structure of the ceiling joists that will have to support the new attic floor.


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## buyingabroad (5 Dec 2012)

Thanks for this picorette. Ceiling joists are definately too light so will have to go with suspended.


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## bacchus (6 Dec 2012)

This [broken link removed]contains valuable information for your project, if you have not got it already.


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## huskerdu (17 Dec 2012)

Tired Paul said:


> Hi buyingabroad,
> 
> Sorry I have no info for you regarding your query but I'm intrested in where you are putting you access stairs - we have a hip roof too. we've been told countless times that we can't get stairs to fit over our existing stirs and still have proper head height with the new access point to the attic.



Hi Paul,
We have a hipped roof and have just had the attic converted. 
We have a standard shape 4 bed sem where the hip of the roof is directly above the stairs, which I am assuming you do too. 

It is true that there is no space above the current stairs. We had the advantage of a larger than average landing (The house was built in the 50s), so we sacrificed half the landing and moved the wall of one bedroom to faciliate the stairs.  It was a big job as a result, but worth it as I think that an attic conversion will always feel poky without a decent flight of stairs up to it. 

Have you talked to an architect with lots of experience of attics to see if there are alternative ideas for stairs ?


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