Loft boarding project started

[danlightbulb]

Started removing some layers of insulation this evening to see what I'm working with.

Ceiling joists are 1.75" x 2.5" approx. 43mm x 65mm. Possibly too small for loft legs so I'm looking at cross battening or adding a new 8x2 floor structure.

Already filled 12 bin bags of old insulation and hardly made a dent. Don't want to remove all of it, just need to remove enough that I can board a section and move insulation from another area into the completed section so I can move around the loft that way.

Existing insulation is not itchy on my skin so it's probably relatively modern coated stuff.

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[danlightbulb]

Yeah that existing stuff looks like rockwool, which is good stuff.

It was difficult to get up, didn't really roll up well so I ended up just tearing it into chucks and stuffing it into the bin bags. Probably makes what I've bagged up non-reusable.

The layer underneath is very compressed. In places there is a different white material encased in plastic bag outer.

 

[danlightbulb]

Do you think I should stick to Rockwool, or is the cheaper glass fibre (Knauf) just as good?

Rockwool is double the price of Knauf.

 

[danlightbulb]

Not sure why you removed the layer between the joists. Fair enough to remove the top layer so you can see the timbers.

In terms of the strength of the timbers, what are you going to store up there? As the boards will run perpendicular to the joists - you will be spreading the load across multiple. If you stick 8x2 over the top you're just adding more weight unless the 8x2 are resting on something load bearing either end.

Tbh if it's just standard stuff you are storing up there, suitcases, a few boxes, paint tins etc. I would just stick loft legs down and crack on. It's supported you - no idea how heavy you are but probs between 80-100kg, and you were probably spreading your weight over 2 joists as you removed insulation? It's not like you're putting a bath tub up there or storing a car in the loft.

I wanted to expose the ceiling to check it's condition, and also expose the internal brick supporting walls which go to the loft floor. Plus after removing the top layer the bottom layer was a mix of Rockwool and some plastic wrapped stuff which I didn't want to keep (condensation trap).

Will be storing Xmas decs, camping gear, diy bits and pieces, suitcases, boxes of books. Yeah not too heavy but there's a lot of it.

I haven't treaded on the middle of the joists yet, I've been working from an area over a brick internal supporting wall.

So yeah I could support additional joists off a ledger board attached to the party wall and resting on the various internal brick supporting walls.

 

[danlightbulb]

Good luck, getting started is often the hardest part.

You've probably seen my thread where I've recently completed my loft, you'll soon feel like Tarzan sometimes swinging between the joists!

Yes Im particularly interested in your insulated loft hatch solution and will come back to ask more on that when I get to that stage.

What type of insulation did you use?

 

[danlightbulb]

The existing product is 170mm Rockwool, although it's not 170mm anymore more like 120mm.

I found packaging with a label attached in the loft. Unfortunately no date on it, was hoping to get an indication how long ago it was done.

 

[danlightbulb]

Another strip light installed into the loft so now have two of these which has improved the coverage.

Something to note on these lights is that they are daisy chainable. However there is no earth terminal so the cable after the first light has no earth protection. Poor design.

 

[danlightbulb]

More area exposed.

Another reason I wanted to get more insulation up is to get to the old chimney area which I expected to be full of rubble and it is.

Now I can see what I have to work with. There is a thick beam over to the far side and a supporting wall nearest to me. Perfect I think for bridging some new framing over.


My plan (please comment if you think its ok or needs refinement):

Ok so the far side timber is 7x3 ish, sitting on top of the 2.5" ceiling joists so I have about 240mm ish of height. I think that will be ok for insulation depth, not quite the 270mm but close enough.

I propose to put a 7x2 timber on top of the supporting wall nearest to me.

Then bridge across to the other beam using joist hangers and either 4x2 or 5x2 timber. The span here is 2.4m, and I would go 400mm centres.

If that 2.4m span is a bit too big for 4x2 or 5x2, I could have another 7x2 joist in the middle (shown in green), which is resting on another brick supporting wall to the left and I would need to attach it to the party wall seen in the picture on the right by means of a ledger board.

 

[danlightbulb]

@Mysterae_ did you use OSB or chipboard loft boards?

 

[danlightbulb]

You really want a small air gap over the top of the insulation under the boards.
It helps move any moisture than does seep up through the ceilings.
Same as why you want an airgap by the eaves.

Thanks I can understand the theory but in practice it's not possible..it's hard enough trying to get 270mm of clearance for insulation let alone another c.20mm for ventilation gap.

I used 22mm moisture resistant chipboard flooring from Travis Perkins but I wouldn't recommend that brand.

I've gone for OSB loft boards 3 packs from Wickes £15 per pack. Same price as the chipboard packs and couldn't see it cheaper anywhere else. Would have been slightly cheaper doing it with full sheets of OSB but didn't want to try and manhandle 2.4m lengths of sheet material through the hatch.

I'll be ok getting timber through.

First batch of timber coming monday - 1x 7x2 3.6m joist, 5x 5x2 4.8m joists which I'll cut in half to get my 10x 2.4m lengths. Total £90 from local merchant. That will be enough to get my first section of frame done. Then I can put some of the insulation back into that section and loose lay some boards on top to enable me to start clearing and building the next section along.

 

[danlightbulb]

Loft light switch currently inside the loft in an awkward spot. Can easily relocate it so...

1. Keep it inside the loft just on the inside of the hatch.

2. Move it to the landing, up near the hatch but either near the ceiling or actually mounted to the ceiling of the landing.

Is it a stupid idea to have the loft light switch in the landing up near the loft hatch?

 

[danlightbulb]

Why are you using timber rather than say loftzone flooring?

Because I don't want to put the load on the existing small ceiling joists. Plus that loftzone product would be much more expensive.

 

[danlightbulb]

Having a bit of a mare with joists setting out and joist hangers.

I couldn't find ones suitable for 2x5 so I bought long leg ones that are height adjustable, but it's awkward getting them in position in awkward corners of the loft.

Then I realised after installing a couple that as they wrap over the top of the joist they will slightly sit proud of the surface affecting the level of my OSB floor boards.

I've ordered some face fit ones now which I need to use instead but these were much more expensive.

It's also difficult to get my joist spacing correct and square. I was working to 400mm centres but the boards are 1220 long which isn't 400mm centres more like 407mm so I've had to redo the joist spacing as well.

Hopefully once I've got the joist work going it will get easier but starting off with the layout it's been quite slow.

 

[danlightbulb]

Section 1 timber joists nearly complete, just a ledger board to fix to wall at the back:

And insulated:

Next section cleared ready for more joists. Plan is a ledger board on the wall at the back, then another 7x2 running on top of the supporting brick wall on the right, with more 2x5 joists then bridging between my two 7x2s.

 

[danlightbulb]

Does anyone have any knowledge about removing these ceiling hangers?

I think they are just anti sag hangers for the ceiling below, but with my new joists I've also used joist hangers onto the ceiling cross members below so I may have made these redundant. The pieces of timber circled are only approx 120mm x 10mm thick, nailed to one ceiling joist at the bottom end and part of the roof structure at the top. They are visibly wobbly not under any tension as far as I can tell.

Anyone have an opinion?

 

[danlightbulb]

I wouldn't touch them

Yeah probably won't. I imagine there's a 99% chance they aren't doing much or my modifications have made them redundant but I can't be 100% sure. Would have made boarding easier if they weren't there.

 

[danlightbulb]

@Mercenary Keyboard Warrior they look original to me, same colour as rest of timber in the loft, same nails as rest of nails I can see, nailed through the ceiling joists which show no evidence of movement. I think they are original.

i dont think they are supporting the ceiling normally. For a start its only one per bedroom, attached to a single mid span ceiling joist. Secondly the ceiling joists already run between supporting internal walls and the outer wall of the house.

My unknown is whether they in any way prevent uplift of the roof structure, rather than prevent sag of the ceiling structure.

 

[danlightbulb]

Second section framing complete.

 

[danlightbulb]

This is the next section I want to do. Unsure how at the moment as I have no solid internal walls to bridge off and I can't see how I can access the external wall plates.

 

[danlightbulb]

Cantilever but you have made it tricky now with how you have laid out the beams
You cuold sister up to the one by the right of the loft hatch and the one on the far left of your last photo

Yeah I left those bits sticking out with the intention of bolting joists together to extend out towards the opposite side there. A full cantilever wouldn't have been possible though I don't think, it's too far a distance compared to the supported distance, and there's still no beam on the far right.

Somehow I need to sit a beam on the wall plate but the issue will be cutting a 45 degree angle reducing the strength at the bearing.

If I add an additional block of wood on top of the wall plate (blue) and then reinforce the cut joist end (red) with a triangular steel plate (green), does this strengthen the bearing end sufficiently? And also could I also bolt the joist to the existing rafters or somehow sister the rafter for extra support?