Why is the attic a tardis!

[oddsocks]

Last week I signed up to have the cavity walls filled and the loft insulation topped up to 270mm. They will be doing the work on 19th June and I had to have the attic clear.....no problem I thought , as we were intending to 'car boot' this year.

After two Audi A6 estate car runs to the tip I still have 2 bedrooms and a bathroom completely full with items from the attic , plus a garage with about 50 pieces of loft floorboarding (not as much fun taking it up as putting it down!).

We have lived here for 15 years but still i was amazed at how much had been hoarded.

Oldest child visited today but never took anything back home with her :-(

I suspect that once the attic has been insulated I will be back up there laying some flooring back down - has anybody done this? Apparently the top up is done in two layers at right angles and over all the joists so they cannot be seen. if I put the floor back down do I:

• - just compress the insulation ...or
  - lay timber where the joists are, screwed through the top ...or
  cut through the insulation (it is crossed) and fit timber direct to the joists.

Also, FYI I have 10 ceiling lights - the advice was to cover them in the attic with 3" clay pots. the fitters will not cover these.

 

[RogerS]

Dave

I'd just stick the flooring straight on top. I assume it's fibreglass type/quilt type insulation rather than Kingspan type? Otherwise you're making a lot of extra work for yourself. Remember where the wires go!

Flowerpots were also suggested to me by my local BCO although strictly speaking you don't need them from a regs standpoint as you don't have a habitable room above. Still with all that extra insulation it makes sense to stop your luminaires overheating.

Tardis attics don't apply only to houses. When working for a couple of years in Halifax, I rented off and on a holiday let. When I was away, the landlord let me stick my stuff up in the attic. Fine until I came to pack everything up on the last day. There I was, fully laden car when I suddenly remembered the stuff in the attic. Not much there, I thought. How wrong. How very wrong.

 

[matt]

I fixed joists at right angles to the existing ones and then fitted flooring to those. If you compress the insulation then I suspect you'll undermine some of the insulating properties by reducing it's abilities to trap air.

 

[MikeG.]

STOP!! Don't listen to Roger!!

Don't stick the flooring straight on top of the joists, otherwise you will have wasted all the money and effort you spent on insulation. Do not compress the insulation at all.

You will have to build in some secondary supports for the flooring, raising it above the new insulation.

Your lights really should be the shrouded type.....but it is also worth checking that your wiring is able to cope with the additional heat. Lighting cable may have to be upgraded or moved.

Mike

 

[oddsocks]

thanks for all the replies.

Roger, I took pictures (there is one cable run that is notched into the top of 5 rafters) and wrote on the roof trusses how far from the corner joint each wire is - so even with the extra insulation down I will know where to avoid any screws.

Mike - I'll follow your advice, the area of floor I need to cover shouldn't cost too much to raise the rafters up. I have felt the lighting cables before with the lights on (they are all low voltage ones) . It wouldn't take too much to rerun them on top of the insulation if needed, as this area won't be boarded anyway.

FYI the cost for the roof to go from about 120mm to 270 in a 4 bed detached was £199 (grant).
The cavity wall insulation is £99 grant + £96 extra (the grant for 4bed covers the first 149 sq metres and my house is 173 sq m). So total cost £394.

The firm claim the true cost off of the energy company (actual cost for both is close to £1k). If I were over 70 or on any specififc benefits it would have been free .

Dave

 

[lurker]

Odd socks

I know what you mean
:roll:
I often lie in bed staring at the ceiling thinking that bluddy lot will come crashing down one day :lol: :lol:

 

[Shadowfax]

Oddsocks,
Think about the heat given off by the lights (I assume you are talking about downlighters set into the ceiling) before you cover them over. If they overheat because there is no air circulation above them you could end up with the roof space alight.
It would solve the storage problem but, perhaps, not the way you would like!
The best information about such luminaires will be from the manufacturers. I would be reticent to cover any kind of downlighter with insulation.
The flowerpot idea is just a way of allowing the insulation to get close to the luminaire while still maintaining an airflow above it. It is not the same as a fire resistant cover, though.
Just my thoughts.

SF

 

[wizer]

I often lie in bed staring at the ceiling thinking that bluddy lot will come crashing down one day :lol: :lol:

Glad it's not just me then. Tho, I can't bare to chuck any of it. It will come in handy..... one day

 

[oddsocks]

Oddsocks,
Think about the heat given off by the lights (I assume you are talking about downlighters set into the ceiling) before you cover them over. If they overheat because there is no air circulation above them you could end up with the roof space alight.
It would solve the storage problem but, perhaps, not the way you would like!
The best information about such luminaires will be from the manufacturers. I would be reticent to cover any kind of downlighter with insulation.
The flowerpot idea is just a way of allowing the insulation to get close to the luminaire while still maintaining an airflow above it. It is not the same as a fire resistant cover, though.
Just my thoughts.

SF

Thanks SF,
all the lights are low voltage ones and whenever I have checked them they are not hot in the attic (just slightly warm). I will get bigger pots though , just for peace of mind.. I will also check after they have finished that the pots are all still visible!

In fact typing this has just reminded me that this is the last weekend to get them!

 

[oddsocks]

Glad it's not just me then. Tho, I can't bare to chuck any of it. It will come in handy..... one day

Wizer - that stuff is in the workshop not the attic....I don't want to think of having to ever empty that lot to get a car back in!

Dave.


PS on a smaller note I mentioned to my wife that we really should sort the drawers in the dining room unit - answer was why, they are full of 'useful stuff'.........she then gave as an example christmas cracker contents!!!!

 

[Night Train]

The other thing to think about with the low voltage lights is the transformers and the low voltage cables. Cables a 12v carry a lot of amps to make up the power (VxA=W) and will get hot. If they are insulated over and cannot dissipate the heat they produce then it can cause the insulation to melt and may lead to a fire. It may mean that you re route the cables and transformers for all the lighting so that it is above the insulation and able to cool down in use.

The same deal applies to mains voltage cables as they are sized based on current, length and run in free air to allow for heat to dissipate. If a cable is in insulation then it may need to be bigger to increase it's current carrying capacity. OK, it won't actually be carrying any more current but it will run cooler as it is carrying less current then it is designed for.

The easiest thing is to always lay insulation under the cables.

 

[matt]

The fireproof covers for recessed lights are to maintain the fireproof integrity of the ceiling between two rooms (or attic in this case). I'm not sure how good they are are stopping heat transfer - the flower pots may be better as they should allow air to circulate via the hole in the base and the heat build up to dissipate more gently.

 

[Derek Willis.]

I had the same problem so I laid my flooring,(T&G chipboard) on top, o/k to start with but it very soon became unstable and the tongues came out of the grooves as it is impossible to fix it.
Derek.

 

[oddsocks]

i've bought the clay pots (22cm version to get the height) and have decided to unplug all the low voltage lights the day before the work gets done. I'll then re-lay on top of the insulation when finished.

Re the floor, I'm going to buy 125*50 (5x2) sawn and raise the rafters to take the floor without squashing the majority of the insulation (top up will be 120mm). Will post photos when done (given the pressure to get the bedrooms back I suspect this will be next weekend)!

 

[oddsocks]

The insulation got laid yesterday and it was a single thickness 200mm roll (which actually when left to expand is closer to 250mm). This was on top of the original 75mm.

I bought 15 x 2.1m x 150x 50 (6*2) sawn lengths to raise the rafters. Because only a single top-up layer had been applied it was easy enough with large scissors to cut the insulation along the lines of the original rafters.

In the new wood I drilled 4 holes 4" 100mm deep and then glued and screwed (100mm pz3 head screws with a long bit) these to the original rafters. Then I laid the old floor back on top and finally ran the down lighter cables on top of the insulation and connected back up.

Total cost for the timber was £72, box of screws and the long bit £6.

Pics....

The before with the 22cm flowerpots visible

And after the insulation applied

In this one you can see how the 6x2 raised beams are level with the new insulation (before I laid the floor I fluffed the insulation back up)

.

Finally, the floor laid. The unfloored area is to allow the ladder to fit. near the far wall you can see the one new row of flooring - some of the old boards were damaged so I bought two new packs, but Focus have made the boards narrower than they used to be (kept the price the same though!)

It was extremely hot in the attic today - far hotter than when I lifted the floor, so that extra insulation is definitely working!

While I was in Focus I checked on the price of loft insulation - they didnt have 200mm but had 170mm. With the buy one get one free offer it would have cost me £150 for 170mm, So I'm happy to pay £199 for a professional to lay 200mm

 

[devonwoody]

I am waiting for the day that they announce that loft insulation is a health hazard, (like asbestos) perhaps they will call it firbreosis?

 

[llangatwgnedd]

Proper job Oddsocks.

Keep an eye on condensation up there on frosty days, as your sarking felt is no doubt not breathable.

 

[oddsocks]

Proper job Oddsocks.

Keep an eye on condensation up there on frosty days, as your sarking felt is no doubt not breathable.

Thanks - I'll have a look when I next up there (refilling the attic from the current bedroom store) to chect that there is still eaves ventilation. The guy doing the job seemed very thorough.


PS I had to google 'sarking felt' as I had never heard the term before!

dave