Insulating and boarding loft for storage

Mendonky

Hi all,

We are getting an extension done and I find myself in need of some storage for items we have in the garage that is being knocked down. I'd like this to be a permanent solution and insulate at the same time ready for winter so boarding the loft seemed like the best solution. Lots of conflicting advice out there so was hoping to ask a few, possibly simple, questions.

Images below for reference:
https://imgur.com/a/8EgBcez

1) Joists (Shown in link) are about 48mm x 65mm (1.9" x 2.55") spaces about 16" apart, which seems slimmer than what I've been reading about online. Would this be sufficient to use board for storage only?

2) I've looked at cross battening vs loft legs- I'm assuming plastic loft legs are out of the question as they're too slim. This gives me two questions:
- With current beams at 2.5 inch, this would mean having to cross batten with something like a 2" x 8" which seems very tall- even then I would not be able to meet a 270mm insulation with space above for airflow?
- secondly, surely this means still having to compress the insulation at sections where the beams cross, as I don't think i can find a layer thin enough to go just between the current joists?

Currently the loft is a mess- electricians have just dumped the insulation back in a pile as seen in the pictures (Assuming it wasn't already like this as I must admit, I didn't look when buying the property 2 years ago)- currently a mix of loose fill in between joists with what i believe is fibreglass dumped on top.

Any advice greatly appreciated

-S

MorningcoffeeIV

Loft legs would be the ideal solution to board over, while keeping the insulation you need.

Mendonky

MorningcoffeeIV said:

Loft legs would be the ideal solution to board over, while keeping the insulation you need.

Thanks- Having researched further The loft legs will actually fit onto the beams.

I'm now looking at loftleg XL (300mm) which would be overkill @ 370mm total depth but would allow for full 270mm insulation with space above and below for breathing.

My main question i suppose is whether my joists are strong enough for the work?

FreeBear

I used the XL (300mm) legs up in my loft - The joists up there are 3x2 (75mm x 50mm), so fractionally larger than yours. Distribute the weight evenly, and any really heavy items, place at a point where the joists go over a supporting wall.

One small comment - Who ever notched those joists needs a kick up the backside. One should never notch over a hole !

Mendonky

FreeBear said:

I used the XL (300mm) legs up in my loft - The joists up there are 3x2 (75mm x 50mm), so fractionally larger than yours. Distribute the weight evenly, and any really heavy items, place at a point where the joists go over a supporting wall.

One small comment - Who ever notched those joists needs a kick up the backside. One should never notch over a hole !

Thanks- not planning to store anything very heavy up there but wanted to check if i was making a bad call investing all this time to do it properly if its going to need joists replacing or something.

As for the notches- I did wince when I saw that, especially with how slim they already are. we had the place rewired when we moved in so no way to know if it was like that before or after!

moneysaver1978

Mendonky said:

Hi all,

We are getting an extension done and I find myself in need of some storage for items we have in the garage that is being knocked down. I'd like this to be a permanent solution and insulate at the same time ready for winter so boarding the loft seemed like the best solution. Lots of conflicting advice out there so was hoping to ask a few, possibly simple, questions.

Images below for reference:
https://imgur.com/a/8EgBcez

1) Joists (Shown in link) are about 48mm x 65mm (1.9" x 2.55") spaces about 16" apart, which seems slimmer than what I've been reading about online. Would this be sufficient to use board for storage only?

2) I've looked at cross battening vs loft legs- I'm assuming plastic loft legs are out of the question as they're too slim. This gives me two questions:
- With current beams at 2.5 inch, this would mean having to cross batten with something like a 2" x 8" which seems very tall- even then I would not be able to meet a 270mm insulation with space above for airflow?
- secondly, surely this means still having to compress the insulation at sections where the beams cross, as I don't think i can find a layer thin enough to go just between the current joists?

Currently the loft is a mess- electricians have just dumped the insulation back in a pile as seen in the pictures (Assuming it wasn't already like this as I must admit, I didn't look when buying the property 2 years ago)- currently a mix of loose fill in between joists with what i believe is fibreglass dumped on top.

Any advice greatly appreciated

-S

I am in the same position - looking to add loft legs and new boards (along with additional insulation) but curious by your original comment: "I'm assuming plastic loft legs are out of the question as they're too slim". Can you provide more context?

The loft is going to be my first and biggest task this weekend as soon we get the house keys!

FreeBear

The foot on an XL loft leg measures 38mm x 89mm, so  plenty small enough to sit on top of your skinny joists - Just happened to have one to hand to measure

grumbler

IMO,  the joists are weak (and loft legs don't make them stronger).  It's better to store heavy things close to the walls supporting the joists and to avoid adding much weight in the middle.

Instead of loft legs it's worth considering adding proper joists next to the existing ones, but this is a big job.

Less perfect solution (but still better than legs) - add new joists on the top of the existing  ones  and screw them with frequent long screws.

ashe

The company that make loft legs also make shelves if it's problematic adding weight 

Jonboy_1984

Have done some legs in part of our loft, around 6sq metres and they worked well, but it is time consuming and quite hot and physically demanding, particularly as you need to make sure you don’t put a foot wrong….once you have the first sq meter in place it is easier to work off that.

It took around 30-45 minutes per sq meter, as you have 8 legs for the first and 4 for any adjacent boards, each needing 4 screws, then fitting the insulation in place and boards on top.

Make sure you have a decent cordless drill with a decent battery(ideally 2) before you start.


(I am also refusing to put any more down in our loft as currently sorting through my parents fully boarded loft with them, and the amount they have hoarded over 50 years is astonishing….!!!!)

Section62

Mendonky said:

1) Joists (Shown in link) are about 48mm x 65mm (1.9" x 2.55") spaces about 16" apart, which seems slimmer than what I've been reading about online. Would this be sufficient to use board for storage only?

As with many houses, that type of structure is designed to support the ceiling below, rather than being used for storage above.  It will bear some additional weight from above, possibly without ill-effect.  The problem with loft storage is that people typically think about the load which will make the ceiling collapse (suddenly) and because that may be quite a substantial amount they think they can get away with using a fair amount of that capacity for storage.

But there are other issues to be aware of.  Increasing the loading will almost certainly result in the ceiling starting to sag.  That sagging may cause cracks in the plaster, and could result in permanent 'bow' in the ceiling.  These are defects that a surveyor would be likely to pick up when you come to sell the property.  These problems will be worse where the structure has been drilled or notched.

People also tend to underestimate the weight of what they are putting in the loft.  It typically starts out as 'a few light items', but ends up being much more.  They also discount the weight of boards they've installed in the loft, and their own body weight as they walk/crawl around in the loft.  It all adds up.

Note also that the use of loft legs tends to change what would otherwise be an approximately distributed load into something more like point loads.  This means taking extra care not to position a leg where the timber is defective (e.g. holes, notches or large knots).

Using a loft for storage only isn't necessarily not as bad a using it for living space - the main difference is in the regularity of dynamic loading (as people walk around), which is greater in living space.  It is really easy to fill a loft up with storage items which in total weigh far more than the contents of a normal lived-in room.  The main difference is converting for living space requires BC involvement which will require the work to be done properly and won't allow bodge jobs.