epsilonGreedy

I would not contemplate this unusual build sequence over a whole winter, I am only considering leaving it standing as a single skin wall for two summer months. The plot is very sheltered, so much so that the longer term problem we have is the village sits in a cold air cauldron surrounded by hills and the overnight temp typically drops 2 degrees below the BBC forecast.

The garage has a lean-to brick shed about the size of a 8' x 6' shed, this helps buttress one side of the inner block wall.

Only one compartment of the out building which houses a store/workshop, this inner wall will be built off a block & beam floor. The inner wall I am talking about is for the non insulated garage portion of the outbuilding. I have been watching a team of pro brickies at work next door and their process is to build up the facing brick wall to about 1.8m high between two corners, then they catch up with inner blocks fitting the cavity batts as the the inner wall goes up.

Thanks for clarifying, I am now using a few brick size blocks on end when the gap matches, it reduces noise pollution in the village.

My facing bricks are due to arrive on-site the second week of August. A veteran builder has looked at my garage and advised that from a structural point of view it would be ok to build the inner block wall up to gutter height as the longest straight run is 5.2m I now have the option of building the inner block wall of my single story garage up to wall plate height before the arrival of the facing bricks. What problems might be encountered building a cavity wall in this sequence? p.s. I won't forget the wall ties.

Yes. I had purchased some for those occasions where I had a 75mm to 85mm gap to fill with a coursing brick on end. Given @Brickie's comments I am not sure if I should use them, though I am struggling to understand the reasoning in the case where a concrete coursing brick has the same density and visual makeup of the full sized blocks in the rest of the wall.

"Fair faced" as in painted? Yes. I purchased some coursing bricks of the same weight and material as the main blocks. If one in 50 blocks is such a matching coursing brick on end would Building Control object?

Yup the Hemlites are 435 wide which explains the fat perps as I kept to gauge following the brickie's tape measure. Ho hmm I can correct this going higher as I am just two courses above the garage floor and the wall is 11 blocks long. Those 95mm cut end blocks will have to be 120mm so keep the bond overlap well above the 1/3 minimum. At least the Hemlites are a regulation 215 high.

My approach is the same, i.e. use a disc cutter to run a 3/4" deep score round all 4 faces, then a few gentle taps with a 4" bolster. I might try a light 5mm disc cut score on two faces and then when laying, rotate the blocks around 90 degrees as per the @PeterWadvice. p.s. Block manufacturers, if you are listening... I would pay £2 for a 95mm x 100m x 215 medium block.

What an excellent trick of the trade, lateral or indeed rotational thinking in practice. Might adopt that.

Got a few of those elsewhere when the coursing maths worked out but when 100mm is ideal those fat perps look ugly and amateurish. As a genuine amateur I have to try harder than the professionals ? Cutting will get more easy once I am laying lighter Plasmor Fibolites (8Kg). At the moment I am laying "paint grade" Hemlites for the car port area of the out building which are the upper end of medium weight @ 15kg per block.

Another point to consider is that a fancy insulation system dictates a floor finishing schedule which might not be convenient for the overall build plan. A standard block floor can cope with 6 months of building traffic as the main structure is erected. Once the roof is on and the building is weather tight and frost proof, then the UFH, insulation and finishing screed can be installed without weather concerns. The recent grand designs series illustrated the problem when that poor retired lady encountered all sorts of delays which resulted in her concrete floor cracking open due to frost damage. There were open window and door apertures which might not have been a concern when the floor was installed in the summer. I assume the water used to pressure test the UFH was left and then ultimately froze.

With standard stretcher bond corners there is a need for a 100mm wide block and I am getting fed up with the dust, noise and delay of cutting a few of these each course. As this must be such a common occurrence across the country I have begun wondering if there is a special block made measuring say 90 x 215 x 100.

When the rain stops I will go and check height of my various block types. And since you mention it my block perp mortar joints have been looking fat as I keep to a spacing plan dictated by my brickie's tape measure, I wonder if my block widths are short as well.

Ah ha, hence facing bricks being quoted as 102.5mm i.e. 4" plus 1mm. This must explain the block 5mm discrepancy. Good thing I requested a delay to dinner this evening, had I not double checked my floor beams would have been seated by just 90mm on my 95mm footing blocks. Not a disaster given the agricultural technology involved but I was mindful of @RA's undersized floor joist ordering hic-cup.

I am about to order a block and beam floor with measurements supplied for my actual block footings. Prior to ordering I spent two hours measuring footing sections with a steel tape measure including the block then I decided to quote all dimensions as clear spans and so subtracted 200mm. This evening while doubled checking the footing plan with a laser, all my spans were out by 10mm too small. A bit of cross checking revealed that my footing blocks are 95mm thick and not the 100mm I had assumed when converting to clear span dimensions. Delving into this further I measured the thickness of 3 different block types onsite. The original footing heavy concretes, the Hemlites and Fibolites were all 95mm thick. Is this normal?

This feels reassuring but is PIR the default choice for underfloor insulation? I thought EPS or XPS was the typical choices, both of which are more spongy I assume. A possible fissure point in a screed flow with UFH pipes embedded would be where the concrete is thinner due to the pipe, in which case we are talking about the strength of 30mm I was thinking of dynamic point loads once the house is occupied. When Swmbo and granddaughter start dancing to a Mama Mia dvd in the static caravan I can feel the loads on the floor.

I am still struggling with the concept of a 50mm crust of set cement resting on 150mm of relatively squashy insulation sheet but that is another thread.

This reminds me of something, hang on... oh yes a distributed system of thermal stores encased in a thermally efficient metal case and individually tune-able per room.

Protek did not ask for all that extra documentation when I took out site insurance last year. The extra stuff you are being asked for sounds like what is necessary for a building warranty.

I like that and completely idiot proof i.e. have the wall-tie dangling from a second higher profile line such that it will obstruct the laying of the block where it should go.

I have started laying my first course of inner wall blocks at a level which requires wall ties. For some reason I keep forgetting ties and have to knock a block off to rectify. Can anyone recommend a fool proof reminder method for wall ties? I am now thinking of stacking the blocks dry with a wall tie sandwiched according to a wall tie plan, then as I lift a block off the stack the tie will fall, then surely I won't forget.

Mortar continues to strengthen noticeably over the first two weeks and as it does so the degree of adhesion between brick courses will increase. Sooner done the better. I would be distressed by that amount of colour variation between courses. When ordering 14,000 bricks last week I was told by my man at the builders merchant then even if the bricks are delivered in batches, the manufacturing depot will ensure I am supplied from the same batch number.

What "thermal efficiency" does 50mm of Supraflo offer over say 70mm of traditional screed. This is what they claim: https://www.cemex.co.uk/supaflo-self-levelling-screed I think they mean improved heat transfer from UFH pipes to floor slab but is this a limiting characteristic of traditional screed with UFH?

Will this be an upside down house with living rooms on the upper floor for sea views?