loft boards

[tom1]

if a loft is being boarded out for storage is it ok to drill through some of the joist for the cables.

thanks

 

[septiclecky]

if a loft is being boarded out for storage is it ok to drill through some of the joist for the cables. thanks

I wouldn't because they are not deep:O:O

 

[tom1]

thats what i was thinking

 

[ianmacd]

Put packers on top of the joists to raise the height of the boards with gaps for cables.

 

[Badger]

or just cut slots round the cable through the boards not the joists



View attachment 276

 

[tom1]

looks the best way badger, i will prob end up moving and pulling up cables, so they can get the Vapour Barrier down, unless they use that foil back stuff, and the cables need to be >50mm as theres no rcd,

 

[androiduk2002]

A bit of knowledge a little off topic , the goverment recommendations for loft insulation have changed yet again from 4 inchs to 11 inchs !!! I say with some confidence this is much higher than all roof joists.

Found this info when I appliedfor a job recently.

http://www.iglooinsulation.co.uk/loft_insulation.htm

 

[Bez]

it is not advisable to cut or drill roof rafters without consulting either Manufacturer or a Structural engineer, unlike floor joists these are stressed in more than one plane, and need different load calculations.

 

[ianmacd]

A bit of knowledge a little off topic , the goverment recommendations for loft insulation have changed yet again from 4 inchs to 11 inchs !!! I say with some confidence this is much higher than all roof joists.Found this info when I appliedfor a job recently.

http://www.iglooinsulation.co.uk/loft_insulation.htmhttp://www.iglooinsulation.co.uk/loft_insulation.htm

They do loft floor boards now that have compressed insulation on the bottom that can be layed across joists and is equiv to 130mm (so with 100mm from the existing joist height insulation gets close to the govt figures).

it is not advisable to cut or drill roof rafters without consulting either Manufacturer or a Structural engineer, unlike floor joists these are stressed in more than one plane, and need different load calculations.

Are cieling joists classed as rafters as I never believed they were?

 

[Bez]

They do loft floor boards now that have compressed insulation on the bottom that can be layed across joists and is equiv to 130mm (so with 100mm from the existing joist height insulation gets close to the govt figures).Are cieling joists classed as rafters as I never believed they were?

Are you talking about a hand cut roof or pre made trusses, either way the timbers will be a lot smaller. It is unlikely you will find 8 x 2 or 10 x 2 timbers holding a roof up. The strength is in the design which is why you should seek professional advice before removing material from roof timbers.

 

[tom1]

http://diydata.com/general_building/roof_construction/roof_construction.php

the loft will be the triditional, not truss. agree that nothing should be cut out,

i have been looking for these loft boards with insulation but the best i found is a floting floor on ridgid insulation

 

[androiduk2002]

I think the most important piece is down the bottom ,

As each truss is designed to form part of the complete roof structure, they should never be cut, modified or their use changed (i.e. replacing a slate roof covering by a concrete tile covering) without consulting a structural engineer.

 

[ianmacd]

Are you talking about a hand cut roof or pre made trusses, either way the timbers will be a lot smaller. It is unlikely you will find 8 x 2 or 10 x 2 timbers holding a roof up. The strength is in the design which is why you should seek professional advice before removing material from roof timbers.

I am refering to the cieling joists that the finished cieling for the room below is attached to not the trusses, rafters, purlins etc..

 

[androiduk2002]

If it is a modern build are those not part of the whole Truss as delivered ?

I would hop up in loft and look but alas I have no loft as current accomadation is a flat roof. :coat

 

[bulmer]

I was always under the impression that ceiling joists were there for one thing.

To fasten the ceiling to and keep it held up.

 

[ianmacd]

They may well be but i understood the requirement was for rafters not being drilled/cut rather than joists.

 

[tom1]

If it is a modern build are those not part of the whole Truss as delivered ?I would hop up in loft and look but alas I have no loft as current accomadation is a flat roof. :coat

http://farm4.static.flickr.com/3465/3241636882_f9d4592e28.jpg

 

[tom1]

I was always under the impression that ceiling joists were there for one thing.To fasten the ceiling to and keep it held up.

you can board out for light storage

 

[ianmacd]

I was always under the impression that ceiling joists were there for one thing.To fasten the ceiling to and keep it held up.

Indeed. The structual part of the roof thats stops it 'splaying' is the collar tie in addition to being fixed to the wall plate.

 

[ianmacd]

you can board out for light storage

I do not think that was being questioned, more that they are joists, not rafters and can be drilled. I would still not recomend doing that on a cieling you plan to put any weight on (i.e. stand) even if its not prohibited.