Loft insulation - for now storage

[Delarge]

I want to use my loft for storage at the moment, with a view to converting it at a later date (keeping in mind all the increased floor strength needed etc)

Our roof has no lining so our roof tiles are exposed with some sort of sand/cement mix holding each tile on which slowly crumbles and drops into the loft space causing a sandy dusty mess everywhere.

there is some old insulation in the loft and no boards down at all

I want to put down some boards for storage and try to stop the sand and dust settling on it

my questions are
1) as i put down boards to avoid stepping through ceiling and for placing boxes etc on should i insulate below and if so do i need to leave an air gap?
2) to stop the sand and stuff falling my thoughts have varied from
a) just covering it all with a tarp (least favourite idea but easiest to do)
b) stapling a damp proof membrane to the underneath rafters
c) rafters are 75mm deep, is there any reason why i cant put 25mm kingspan leaving the required 50mm air gap and board over in the half i am going to use as storage? keeping the crap from falling on my stuff and reducing the size of the job in the future when i board out the rest?

 

[PrenticeBoyofDerry]

1) no gap needed, full fill. But the recommended depth is now 270mm of insulation (rock/mineral wool) so you might want to increase it by lay joist at right angles to your existing loft joist, so raising the floor level and allow more insulation layers. and the floorboard/panels to be laid.
2) c could be the best option, but what material is your roof tiled/slated with, could be important that it gets repointed.

But if you ae considering using this space for something other than storage, consider your options first.
Is it worth doing any time consuming and costly work, if you are going to converting the loft in the near future, where structural problems (floor strength, breaking in to your roof to provide light or/and space.
I would look in to that, first.

 

[mointainwalker]

You need to consider when you are going to convert the loft. when you do so, all the insulation above the ceiling will need to be removed, so if you have put down extra joists and insulation up to 270 mm , this will considerable extra work and wasted cash.

If it is in the near future, it might be worth while just inslating to the top of existing joists as fibre insulation is currently so cheap.

 

[Delarge]

so having insulation under the floor in the loft and in the rafters is not
a)necessary?
b)advisable?
c)counterproductive?

with 75mm rafters and only 25mm kingspan unless i add thickeners to the rafters the insulation will be poor once the loft is converted, i had assumed that the floor insulation would help the main house and the lesser insulated loft would be colder - is this a bad solution?

 

[mointainwalker]

"with 75mm rafters and only 25mm kingspan unless i add thickeners to the rafters the insulation will be poor once the loft is converted, i had assumed that the floor insulation would help the main house and the lesser insulated loft would be colder - is this a bad solution? "

My comments about not insulating are directed at the 270 mm solution which involves big effort and expense and would sunsequently require removal.

Whether you insulate on the ceiling when you convert is up to you and depends on how you intend to use conversion.

If it is to be a fully usable room, then many people would not insulate between joists as this allows you to benefit from heat rising from below, however you might prefer to stuff cheap fibre-wool in there because this is also sound-insulation benefitting (principally ) the rooms below.

 

[PrenticeBoyofDerry]

If the loft is for storage, insulate between joist in ceiling void only. It is not necessary in the sloping roof.
But if you intend to make it a habitable room, then no need to insulate in ceiling void, but recommended in sloping roof.

 

[JohnD]

It's my opinion that conversion of the loft to habitable space, which will cost many thousands of pounds if done to a level that satisfies Building regulations and will not send potential buyers running screaming from your door when you want to sell it, is not going to happen anytime soon.

So I would approach it as a storage loft job.

Insulate the loft floor fully. Rolls of insulation quilt are heavily subsidised this winter, and I even saw in Wickes an own-brand copy of Space Blanket in long rolls with a plastic keep-clean covering (not metalised) at a cheap price.

Where you want to put a storage floor, either counterbatten it so you can put an extra layer of quilt over the timbers before you lay the floor; or after filling between the timbers with quilt, lay a rigid insulating foam slab, and fix your flooring through that. You will find a display using expensive Knauf foam in most DIY sheds, but I can't see any reason why it wouldn't work with cheap polystyrene slab.

Some people staple rolls of thin insulation to the rafters, its like bubble-wrap with reflective layer on it. You ned quite a lot of it,so it is not as cheap as you might think. It will at least stop some of the grit falling down onto your collection of christmas trees and Diana Ross records.

Be aware that loft floors are economically designed to have enough strength to hold the ceilings up, if you have anything heavy, or several people, up there, your ceilings will bow and crack, and your piano might even fall through. Converting a loft so it is strong enough for a habitable room is an expensive job, and beyond most DIY. Bodged conversions are undesirable as it costs a lot extra to strip them out and do it again properly.

 

[surplus6]

sorry for the hi-jack, but it sounds similar to the question I was going to ask.
My loft is for storing my dianna ross lp's and the like, I have boarded it out to enable me to walk round without putting my foot through the ceiling, my roof is the same with exposed tiles with the cement holding them in place. my question is has anyone heard of a spray on coating that could be used to seal the roof? 9to stop the crud falling) I had heard of it years ago, but google doesn't seem to want me to find any. anyone know?

 

[SidDIYer]

Has anyone tried these boards from B&Q ? B&Q Insulated Timber Loft Board

They don't state what the U-value is.

 

[JohnD]

it's a bit of chipboard glued to a bit of foam slab, at a ridiculous price