Topping up loft insulation

nccgtr2

Hi,

I am looking into topping up our loft insulation.  but i am not sure what to go for or if its worth it.  We currently have about 150MM floor insulation that is topped with two layers of fully fitted 10MM thick large chip board making the whole floor walkable.  The space is used.  I want to put some insulation (100MM ideally) over this but want to walk and store the current stuff on top.  There are file cabinets and other weighty stuff up there.  Is there tough insulation board out there for this?

Also the rafters are insulated to about 100MM.  Again I was thinking of doubling this too?

Is this all a good idea or is what i have good enough?

singhini

i know nothing about loft insulation, but i too thought about increasing the loft insulation thickness on a previous house i lived in and a local builder told me that if you increase the thickness, its important to make sure you have the correct ventilation aswell (otherwise you get moisture building up which can lead to mould).

Having said that, a quick google search suggest the minimum thickness is 270mm (while some homes can be 400-500 mm), so there might be the scope for you to increase, not sure?

Hopefully a there's a builder (or others) on this forum that can advise

Albermarle

Current thread.
Loft insulation etc - worth it if moving house in a few years? — MoneySavingExpert Forum

nccgtr2

Thanks, sounds like a good idea.  I was thinking of doing this myself but can you walk on floor insulation?

GDB2222

nccgtr2 said:

Thanks, sounds like a good idea.  I was thinking of doing this myself but can you walk on floor insulation?

I don't know of any you can walk on, and it sounds like you haven't found any either.

I would take the chipboard floor up. Put timber on top of the joists, to raise the floor level. Stick insulation in the gaps, and put the floor back. Or you can get special legs to raise the floor.  

Obviously, you can do it in sections, so you don't have to take everything out of the loft!

sheenas

 nccgtr2  You can't, but you can get legs/stilts for the boarding and then the insulation goes underneath. 
In terms of thickness of insulation up to 500mm, it's more about what you can afford.  

ComicGeek

nccgtr2 said:

Hi,

I am looking into topping up our loft insulation.  but i am not sure what to go for or if its worth it.  We currently have about 150MM floor insulation that is topped with two layers of fully fitted 10MM thick large chip board making the whole floor walkable.  The space is used.  I want to put some insulation (100MM ideally) over this but want to walk and store the current stuff on top.  There are file cabinets and other weighty stuff up there.  Is there tough insulation board out there for this?

Also the rafters are insulated to about 100MM.  Again I was thinking of doubling this too?

Is this all a good idea or is what i have good enough?

What is the current 150mm floor insulation? If it's a rigid insulation board, then that's probably sufficient without going through the hassle of adjusting the chipboard flooring. If it's loft quilt squished below the chipboard then it might be worth the effort to top it up.

What is the insulation between the rafters though? And do you have good ventilation in the roof space? Normally you only insulate the floor, and keep the rest of the loft cold and draughty.

nccgtr2

Thank you for the help guys.  I dont think i will do the floor because i cant do with the faff of lifting a double floor.  

The insulation under the boards is fibre roll to my knowledge.  The roof gets cold in winter and hot in summer.  Its always nice and dry.  To my knowledge the ventalation is good..

GDB2222

The attic is *meant* to be cold in the winter! The eaves are open, so there’s plenty of cold air coming through.