markc

Never glued a chipboard floor, always full thread screws and boards pulled down tight to joists before fixing.

Not all but many are interchangeable

Slate doesn’t cope well with direct heat, if you sit the fire pit on something insulating like a few layers of cement board it should be fine, assuming it’s a raised metal type

I have just done an old floor with 150mm joists. Even from above was a pain because all the joist spacing varied slightly. Can’t imagine how hard it would have been from below in a 4ft high crawl space.

Nick summed it up nicely, leave it as storage, or buy another house it will be cheaper and less hassle.

Good morning and welcome. Loads of priceless information on here, try searching first and then ask away. and I’m sure your knowledge of groundwork’s will come in handy.

A UB would be much better than a UC. And increasing the depth would make a massive difference. weight wise a deeper beam would be lighter than a UC. 25mm deflection is a ridiculous amount and would create many more problems. pre cambering would definitely help,

We were taught how to wire a plug and repair a wired fuse at school

As Prodave said, what’s supposed to be wrong with it?

Not an expansion joint, doorways are crack points. the screed will shrink and crack, while wet cut a slit at least half the depth of the screed across the door threshold. This causes the crack to form where you want it.

Octopus were fantastic when I wanted a 3 phase meter putting in. Cable was an old existing.

There was a similar thread last week regarding this. I personally can’t see the point in double slabs if the ground is good and compacted hardcore is there. bbut if I remember correctly one or moreBCO’s had wanted the sub slab

+1 to @Marvin comment

f I shorten a galvanized roofing strap will the exposed bare metal ends trigger runaway corrosion and failure within a few decades? nope! Galvanised steel is deemed self healing. You will probably find the straps have cut ends anyway. galv sheet is treated full size and then sheared to size for use when building trailers etc.

Take cost out of the equation and steel still wins hands down for this application. the skylights would require SE input for timber as well because the application / load tables do not allow for your large and presumably very heavy skylights

Perforated drainage pipe (single or twin wall) geotextile laid in bottom of excavation and up the side, clean ballast/pebbles etc. (No fines) under and covering the pipe, textile over the ballast and then backfill with anything as long as it’s not heavy clay.

Galv’d not halved ?

Too many variables to have a guide. if you cut one rafter you double the two adjacent ones. After that it gets more complicated. Even the position of the roof light/load within the rafter length has a big impact on loads.

Haha, once spent a whole day flame cutting halved steel structure … that evenings “hot and cold shakes” zincpoisioning wasn’t pleasant ?

Right, now cutting 6 rafters would put up and extra 3x load on adjacent rafters. this may require them to be made deeper, not just doubled or trebled. Plus weight of roof light itself also needs factoring in. sounds like this job could do with SE input. Cutting one rafter for a velum etc on a pitched roof is much more straightforward.

All depends on which way the joists/rafter run and which way around the roof lights are. Much more involved than just doubling

I like his style log store that doubles up as an air raid or earthquake shelter

Are you sure it’s sand? Looks more like Demarera sugar. looks too course for ordinary (red) mortar sand, maybe a local sharp sand so should be perfect for concrete or screed

Well, you learn something new everyday

If there is no gap at all then I would cut/scabble the concrete back a bit.