Roof insulation

[slowjo]

Hello helpful people.

I'm really useless and need abit of advice. I've recently bought a house and its loft has been professionally floored for storage space. I'd love to also use the space by putting my pc up there. Before doing this I would need to insulate and board up the rafters, as i can see the slates.

Now, can I just buy any old insulation and stick it next to the slates and then board it up or is there a proper way to do this without costing a fortune?

All help will be very much appreciated.

Thanks.

 

[shenks]

When you say 'professionally floored' do you mean it has new floor joists, trimmers, and boards? Or do you mean it has very neatly laid boards on the ceiling joists?

The only reason for asking is ceiling joists are there to hold up your ceilings, not to support fixtures and fittings and a thousand other items.

Once this has been clarified then you can start thinking about celotex, kingspan or similar for between rafter and below rafter insulation.

 

[slowjo]

Thanks for the quick response.

To answer your question it has very neatly laid boards on the ceiling joists.

 

[JohnD]

Probably not strong enough. What size are the timbers?

 

[slowjo]

Sorry for sounding silly but what timbers?

Do you mean the timbers of the roof? Which the slates are attatched to?

Kind of hoped I could just buy some sort of insulation. Put it between the rafters (next to the slates). Then board up the insulation with some sort of boarding. I'm guessing its not as simple as that?

 

[masona]

Do you mean the timbers of the roof?

No, it's the ceiling joists where the floorboards are, most common size are 4"x2"

 

[Deluks]

or to put it another way, are the boards laid directly onto the joists that support the ceiling below?

The ceiling joists for the bedrooms etc. are there only to hold up the ceiling, not for storage of heavy items or walking about on (much)


It is not intended for use as a floor, and laying floorboards or chipboard panels onto it still doesn't make it so. Professionally floors would mean strengthening the ceiling joists, or putting new joists to support the new floor.

When you bought the house were you shown any documentation that suggests that building work was carried out to reinforce the floor. (You can find out at your local council planning dept.)

Although as stated, 4x2 is usable provided you don't overload it.

 

[slowjo]

Ok I've looked through all the stuff I got when I moved in and I found the receipt from the company who carried out the work in the loft.

The Floor size they laid was 648 sq feet

on the notes it states
Kingpin 3"
Plasterboard Ceiling 2.6M

(Means nothing to me!)

It does not state anything about extra joists or strenghtining of the roof timbers. You thought it would have for the price they paid! lol

Hope this helps a little.

 

[JohnD]

Could it be "Kingspan?"

What size are the timbers that you can see (pref at the edges of the floor, else on the slope).

If you stand on the ladder in the loft hatch, what is the measurement from the undersurface of the ceiling, to the top surface of the flooring?

 

[slowjo]

Thanks for the quick reply.

The receipt definately says kingpin 3"

Measured the ceiling to loft floor. At the hatch.

Its 9" in total. Which looks like it comprises of 5" of it being Ceiling to orignal floor. Then the next 3" looks like what they've added to maybe level the floor. (more timber) Then 1" hardboard for the flooring itself.

 

[masona]

Can't make up my mind if they added timber on top of existing joists or use bigger joists side by side. Can you do a photo of the joists section?

 

[slowjo]

It looks like they have added timber on top of existing joists but again I'm not sure. Where would I need to take the photo? The only real place is at the hatch.

The house house ws built in 1940 if that helps.

Thanks again for all your help guys. Keep it coming.

 

[masona]

It looks like they have added timber on top of existing joists but again I'm not sure. Where would I need to take the photo? The only real place is at the hatch.

Is it possible to take 1 board up to have a look

Is the whole loft area boarded

Can you not see it at the end

 

[shenks]

slowjo - as you are discovering there can be a whole world of difference between thinking you have a 'professional' job and realising what you don't have is something which meets building regs.

At the end of the day, there is no point doing a job (or paying somebody to do a job) unless it is done correctly. Otherwise, you just create problems to be tackled at a later date. It's just unfortunate that the previous occupants didn't realise this.

Was the loft mentioned in the house sale details as being professionally converted/floored? If so then you may have a valid argument to raise with the estate agents - it all depends on the exact nature of the flooring job and how it has been built.

Hopefully with the assistance of people on this board you will be able to clarify what you really do have in your loft, and then progress with your original project of insulating the roofspace.

 

[slowjo]

I've checked the sales details from the sale. It just states floored loft space. I do have the receipt for the work so I could call the company who carried out the work. I will do this after xmas and see what they say. I'd imagine they'd be able to tell me exactly what they have done.

Thanks for the help.