any advice on flooring an attic

doshin

I was thinking of putting a floor in my attic and i'm looking for some advice. Can i lay sheets of ply, if so what thickness would they need to be? Is there any need to put extra support between the joists?
extra space is just for storage so aesthetics of the floor not that important.
thanks in dvance

Raytown Rocks

Hi Doshin
I floored part of my attic years ago. Not sure what size ply it was tbh, fairly standard though. What I would recommend is measuring the opening in the attic entry prior to buying the ply wood. Then have the builder/provider cut the ply so it fits into the attic. ( I realised this the hard way...spent ages cutting boards)
Also if like me its an old house you may find some electrical cables are surface run on top of the joists, You will need to go around and cut a groove in all the joists/beams to lie the cables into so that the ply sits flush on top.

These are some simple things, I'm sure some people will have a lot more professional ideas that may help.

Good luck

Chef

Corkey123

Sooner use the chipboard flooring slabs. It is stronger than ply, probably cheaper and because they come in slabs it will facilitate you if you need access to any electrics from the attic. They shouldn't require any extra boasting of the joists.

doshin

thanks guys. I saw those chipboard sheets but assumed ply would be stronger.

corm500

Yeah I was thinking of flooring my attic also, but I was wondering what the best flooring would be. I'm a heavy guy (20st) and worry that certain materials would not hold my weight too well.


Corm500

DamoKen

doshin wrote:

thanks guys. I saw those chipboard sheets but assumed ply would be stronger.

I put down the chipboard sheets last year and haven't had any problems. Admitedly I don't go up to often and the joists are fairly close together, about 1.5ft apart I would think, but they do the job. Got them cheap as well in Woodies I think, just slot them together and drill them in, finished in 1/2 a day including time to cut around pipes & wires going over joists.

Hagar

Are those chipboard sheets tongued and grooved? If they are they will not be easy to take up for cable access.

A router used across the joists is a handy way to hide the cables. Not too deep though.

If you have any scrap battens lying about screw them to the edges of the flooring to make a mini wall when you have the floor down. It will stop stuff sliding off the edges of the floor and maybe causing damage to your ceiling.

DamoKen

Hagar wrote:

Are those chipboard sheets tongued and grooved? If they are they will not be easy to take up for cable access.

good point Hagar, yeah they are. As most of the main cabling is off to one side under the eaves it wasn't too big a concern though I do have one water pipe running under it as well as a cable for the bathroom light. Would have prefered to just get straight edged boards but they were going cheap so ...:)

Carpenter

MartinCorcoran wrote:

Sooner use the chipboard flooring slabs. It is stronger than ply, probably cheaper and because they come in slabs it will facilitate you if you need access to any electrics from the attic. They shouldn't require any extra boasting of the joists.

Hi
The chip is not stronger than ply thats for sure but it will do the job ok

Desmo

MartinCorcoran wrote:

Sooner use the chipboard flooring slabs. It is stronger than ply, probably cheaper and because they come in slabs it will facilitate you if you need access to any electrics from the attic. They shouldn't require any extra boasting of the joists.

My joists are very modest thank you.

Des

JamesM

I used chipboard, that was meant to be suitable for attics, about 15 years ago. It was very weak and I had to mark where the joists were and only walk on that area. I took it all up last year and used tongue and grove floor boards, lightly screwed down - quite cheap and easy to use.
Jim.

GreeBo

JamesM wrote:

I used chipboard, that was meant to be suitable for attics, about 15 years ago. It was very weak and I had to mark where the joists were and only walk on that area. I took it all up last year and used tongue and grove floor boards, lightly screwed down - quite cheap and easy to use.
Jim.

What size was the chipboard?
Mine is about 3/4" and is very sturdy..
Im assuming you laid it *across* the joists :eek:
What was the span?

SoBe

chef wrote:

You will need to go around and cut a groove in all the joists/beams to lie the cables into so that the ply sits flush on top.

this is not recomended as it could have adverse effects on the structure of the joist's

if you have cabels running over the joists you are better off counter battening the floor

JamesM

GreeBo wrote:

What size was the chipboard?
Mine is about 3/4" and is very sturdy..
Im assuming you laid it *across* the joists :eek:
What was the span?

It was about 15 years ago. The chipboard was sold as being suitable for flooring an attic. I think that the sheets were about 3ft by 2ft. I can't remember how thick, maybe only 1/2". The span is about 18". Chipboard does not have a grain, so i'm not sure if it matters what way it is laid. There will always be an overlay if you lay 3' by 2' across an 18" span.

I find the tongue and groove perfect, as a board can always be cut to end on, or close to, a joist.
Jim.

Tidyweb

I laid 4X2 across my attic joists.

Now I want to screw them down. I assume I should screw in 2 screws at 45 degree angle on either side rather than a screw down the middle of the 4x2.

What length and size screw would you use.

Corkey123

Screw right into the joist (be careful of electrics) Screw are just for keeping flooring in place so use screws an half inch to an inch longer than the thickness of the 4x2

Tidyweb

An electric shower cable runs through the attic.

This is now covered by 200mm of insulation.

Is this safe.

I assume electrical cable and heat can mix easily enough

Corkey123

Not sure why you are referencing heat - there shouldn't be any heat out of electric cables (unless the shower cable is not up to the required spec)

There can be heat from recess lighting in the room below but other than that you shouldn't have a problem

Tidyweb

so its fine to cover shower cables in insulation

Corkey123

Yep - no problem

Liamalone

Anyone have any bother with mould underneath their solution?

Moved into house Dec '11 and put down a couple of discarded flatpack wardrobe doors as I sorted out tv aeriel and Sky to bedrooms. Just the other day I was up with a view to putting down chipboard for storage needs and found some mould under one of the doors I had set down.

The insulation is about 100mm and the depth of the joists so when the door was set down it was touching the insulation - mould was on the insulation and on back of door, admittedly stuck to some insulation, also on top of th joist too

On a sidenote while I'm here, up north btw, builder has approx 100mm of insulation in place but reg's as of circa '06 state that it should be 270mm. He says that because the house plans were passed circa '00 the new reg's don't apply. Is he taking the proverbial?

BryanF

This could be a number of things.
Is there adequate ventilation of the roof space?
Is there a vapour control layer beneath the insulation ( above the plasterboard)
Any sign of leaks etc?
What type of insulation is it?
The PIR / PUR products ( like kingspan et al) are not the best between timber joists

As regards thickness - you moved in in '11 so it was built When?
Sounds to me like the builder is taken the mick alright , but i always worry with things like this, what other shortcuts may have been taken. Did you have an architect certifying the build? Did that arch do a detailed spec or drawings?
What I would do is write to builder outlining your concerns and what you feel is missing. Explain that if it's not fixed to your satisfaction you'll be employing an architect or building surveyor and if they agree with you assessment you'll be writing again , this time expecting not only the work done but the professional fees paid for also.

BryanF

I meant to say also if the mould is inside to rooms, what's the room ventilation like? Often times the premavents are not enough and spaces need daily opened windows

Liamalone

Cheers for the swift response, much appreciated Should've mentioned that this is a new build house and we are first time buyers so probably a bit wet behind the ears about certain things that wiser folk might be inclined to co before buying.

BryanF wrote: »

This could be a number of things.
Is there adequate ventilation of the roof space? Standard ventilation I'm told, a vent at either end of roofspace that vents out on the underside of the fascia board below guttering.

Is there a vapour control layer beneath the insulation ( above the plasterboard)? None as far as I noticed and I have been hoking about taking a power supply from one of the ceiling rose.

Any sign of leaks etc? none that I noticed, will keep an eye out next time I'm up

What type of insulation is it? Seems to be your standard fibreglass stuff, beige coloured, hateful to handle lol

The PIR / PUR products ( like kingspan et al) are not the best between timber joists

As regards thickness - you moved in in '11 so it was built When? Built mid '11
Sounds to me like the builder is taken the mick alright , but i always worry with things like this, what other shortcuts may have been taken. Did you have an architect certifying the build? Did that arch do a detailed spec or drawings? No, house is part of an estate, our house number is in the early 100's so there's quite a few of the same type already up from around 2001.


What I would do is write to builder outlining your concerns and what you feel is missing. Explain that if it's not fixed to your satisfaction you'll be employing an architect or building surveyor and if they agree with you assessment you'll be writing again , this time expecting not only the work done but the professional fees paid for also.

Tis only a few weeks ago that I nailed him down to come around and look at my 'snag' list, even then I think he palmed me off on quite a few things. Time to get my angry/tough head on lol

Many thanks again


edit:

BryanF wrote: »

I meant to say also if the mould is inside to rooms, what's the room ventilation like? Often times the premavents are not enough and spaces need daily opened windows

Only issue with mould is on the topside of the insulation in the attic where a door was lying on top of the insulation - The attic was fairly warm when I was up the other day and noticed it but that was in the heatwave we had there. Windows around house have them wee trickle vents at the top but I have had them closed since we moved in to keep the heat in lol

1865

It is important that you check if the joists are cpapble of taking weight. In modern houses, the roof timbers aju just about strong enough to take wthe weight of the roof so if you add in the weight of board you may be placing a strain on the roof. This is all before you load up the attic with junk.

BryanF

Liamalone wrote: »

Cheers for the swift response, much appreciated Should've mentioned that this is a new build house and we are first time buyers so probably a bit wet behind the ears about certain things that wiser folk might be inclined to co before buying.



Tis only a few weeks ago that I nailed him down to come around and look at my 'snag' list, even then I think he palmed me off on quite a few things. Time to get my angry/tough head on lol

Many thanks again


edit:



Only issue with mould is on the topside of the insulation in the attic where a door was lying on top of the insulation - The attic was fairly warm when I was up the other day and noticed it but that was in the heatwave we had there. Windows around house have them wee trickle vents at the top but I have had them closed since we moved in to keep the heat in lol

did you get a ber? also your engineer / solicitor should have the paper work re compliance to building regs and what planning permission date etc.

the condensation in the attic suggests a lack of vapour control layer on the ceiling, you insulation levels are not up to scratch, but the vapour thing is also worrying - you should be airing the hell out of the house as things need to dry out! the windows should be open as much as possible

DPM1

My attic is partially floored along the length of the building but i am interested in bring the attic insulation up to standard as it seems poor and missing totally in more places. I will probably do it via the seai scheme in conjunction with the cavity wall insulation.

How does this work with an attic that has been floored as i believe that the insulation should not be compressed or is there an tips to flooring an attic that has the latest insulation installed?

richiek67

I got white deal tung and grove for my attic in B&Q. I don't like chipboard and wanted some light reflected off the floor. It worked out well. Getting the 12foot planks into the attic wasen't too bad either , looks good too and actually at the time worked out better than the old chipboard, lighter too!

Rich

StevenSimmons

I placed a light above my new kitchen cabinets in such a way that the light get reflected from a flooring and the celing paint with a faint color and wall also painted with a faint color. So that the light emits through out a room. It's looks great.For more information on this topic visit this link.
http://www.thertastore.com

dodzy

StevenSimmons wrote: »

I placed a light above my new kitchen cabinets in such a way that the light get reflected from a flooring and the celing paint with a faint color and wall also painted with a faint color. So that the light emits through out a room. It's looks great.

I'm still trying to decipher this post....

Chippy80

Use 8 ft x 2 ft OSB tongued and grooved all round . You won't need to land ends on joists either !!
Good strong job.

Can be bought from almost any builders providers.