If you have two zone valves you can run the systems independently, (need two thermostats) I find this useful this time of year I leave my floor on 24/7 (low) the house rads programmed to come on and off as needed.
Yes it's a tie, tap with a hammer to knock off the mortar, mix up some more mortar and push the tie into the new bed of mortar... lay your brick/block on top of it, you shouldn't need to support the brick/block.
Good luck
You may well have a weep on the rainwater pipes, water could be tracking down the pipes.
Condensation could be forming as there is probably little or no insulation in the roof.
You would need to pull some of the ceiling down to investigate.
Easiest fix would be to bond some insulated...
Looks like my raised collar roof, with insulation applied years ago, minimal air gap, all it still good and dry.
If worried, see if there is room to install felt vents, failing that, perhaps you could install eaves vents.
I would have thought if you had a leak and it was buggering up the floor, you'd have spotted this by now.
Looking at your images, I think it's still too tight to the skirting. Wood moves more across the plank than it will lengthwise.
You should have a suitable expansion gap on all walls (8mm...
Is this solid wood or engineered?
Do you know if there is an expansion gap at the wall? If you're not sure, perhaps pull up a section of the beading next to the wall.
If there is no gap, this could explain why its warping.
How many tiles are loose? How bad are the cracks?
If there are lots of cracks would be better taking tiles off, self levelling (if needed), installing a mat, then re-tile.
It's quite a job though.
I have similar floor with mat. Last year I advised customer to fit a mat, they didn't listen and...
If you only intend replacing the bricks above the door, then remove these and bin the rotting wood, you can install a concrete lintel, then replace the brickwork on top of this (if the wall is 9" thick (brick longest length) then you will need two 'single concrete lintels' side by side.
Only...
It will always be a little damp in there being single skin and unheated. In the colder months some rust spots may appear on metal items stored in there.
If built properly it should be water-tight, but you could consider cladding it, in either wood (cheaper) or cement board cladding (dearer)...
Well if it was me, I'd try a sample brick with either a wire brush type thing on my drill/angle grinder or paint stripper, no way would I pay what you've been quoted.
Think you can get it blasted but not something I have knowledge on.
Good luck
No need to mortar, just butted up, I did add flaunching around the sides.
They were straight runs, but had to mitre the corners, I used a grinder, but it's dusty.
This may help, I recently set some charcoal pavoirs (80m) on 10:1 semi dry mix (got from the 'bedding' section on this link.
After a few days it was very solid.
Paving expert - Edging
I was suggesting building up the slope in thinner sheets of PIR.
Like stacking 25/50mm sections until you get to nearly level, filling any voids with expanding foam.
You can then go over all of this with the 100mm and 65mm screed. The screed will take care of anything not level/ridges etc.
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