gavztheouch

This picture Shows the rebar better. A393 is 200mm squares so within a 200mm block there should be at least a 50mm by 50mm hole. Some sheets are perfectly out of phase ie 50mm by 50mm holes and some placed directly on top of each other so the hole in the layer Is 200mm by 200mm. There is also every other possiblity as the sheets drift in and out phase with each other.

The concrete contractor suggested 10mm aggregate, I was worried this may make the concrete shrink more as there is more sand water and concrete in the mix of the smaller aggregate size.

Thanks Gus I'll send him some pictures tomorrow. Looks like Thursday will be too wet to pour, we have thundery showers forecast which could be nothing or loads of rain so prob not worth the risk. The mesh is A393 two layers on the bottom and two layers on the top. 400mm overlaps with flying ends which helps with congestion. I offset the joints in the sheets to reduce congestion in the same point. I think the pictures looks a lot worse than how it looks in real life, especially the parts with water underneath causing reflections that look like more bars . Maybe I should wait until more of the crew gets back on Monday so I would be more free to use the vibrator poker.

Booked in for this Thursday with the original contractor. He is on holiday but his son is still here with part of the crew so we are going to work together to see if we can get it done.

Been let down slightly by my concrete contractor who was going to pour over the last two weeks but hasn’t managed it and is now unfortunately going away on holiday for two weeks on Monday. The concrete pour was the bit I was dreading and I felt good when I finally found him as he gave me some confidence he would do a good job. It’s mainly my fault I’m in this situation as I have been too busy to push the foundation on as fast as I would have liked. It now leaves me with a difficult decision of finding someone else short notice or waiting what could be up to a month for him to come back and find another weather window. This will set back my stick build big time and push me into the winter months which I was trying to avoid. Feeling a bit anxious about the whole thing. This must be the stress everyone I talk to about building a house must be talking about! I’m in central Scotland. Anyone know someone who can pour a slab that will have a power floated finish. The concrete is going to be the finished floor surface, hence the worry/disappointment that I may be forced to go with someone else in a bit of a hurry after spending aging finding someone I could trust.

Thanks Conor, so you actually lowered the bath/feet/base into the recess, or the recess was for plumbing?

Hi I am building a new build with an insulated raft. There is a bathroom with a bath on the ground floor and the structural slab concrete is the finished floor. I already have my soil pipes and rebar mesh in the isoquick insulated raft but I have not yet poured the concrete. My architects drawing specs a recess under the bath for plumbing. I have watched a few YouTube videos and had a look under my bath in my flat and the water trap does not go below the floor in any of these examples. What is the benefit of having a large recess under the bath. I guess some baths will have very low drain holes I guess that could be an issue. I have one soil pipe next to the bath to accept the water from the bath plus a toilet and sink. Having the soil pipe recessed down inside the 140mm deep recess may give me more run/height for the toilet, bath and sink connection’s especially as I will need some special connection to bring all 3 together. I am hesitant to remove the top two layers of a393 mesh to make the recess in the concrete as it very close to the edge of the slab.

Build to near or at passive house level. Then you won’t need to worry if you lose a loop of pipe.

I pressure tested it last week before the damage and will do it again tomorrow. Im fairly certain it will hold pressure. I guess I was worried about future leakage but I'm not sure how that would happen incased in concrete.

I have damaged a pert-al-pert pipe in my foundation. For context it is under two layers of A393 mesh which will make it hard/take time to fix. Feeling gutted as I was almost ready for pouring concrete and this will set me back if I need to fix. I damaged it by swinging a metal pole to hit the rebar mesh to move it and I also hit the pipe. Do you think it is too badly damaged? I would say it's prob ok but it feels border line which is annoying. Im so tired with work and this foundation that my judgement may be impaired a little. I hasn't exposed the Alu core. Options. 1. leave as is, maybe wrap with some tape just incase the concrete does manage to somehow effect the aluminium core 2. repair with a coupler Cheers Gavin

Hi, what spacing are you using on your continuous chairs. Looks about 600mm? My first row I’ve done is 800mm thinking about reducing it to 600mm. I’m going to have 3 big lads standing on it pouring the concrete. Don’t want the chairs to spread/squash down and lose height.

DPM and first layer of mesh.

My engineer has specified I give 40mm cover to the rebar top, bottom and sides I noticed my 105mm high chairs are more like 110mm. My isoquick is not 100% flat. I cannot buy high chairs the exact size need to give me the correct cover top and bottom. Some of the mesh is bent which will creat high and low spots. These are just a few reasons why it is practically difficult to achieve 40mm cover without a massive tolerance of say ~20mm I have called and emailed my engineer but I’m worried he is away on holiday as I have had no response. I can’t afford to wait around so I’m thinking about dropping my bottom cover to 30mm as this will be easier to achieve. Top cover will be aiming for 40mm but I know there are some high spots of at least 8mm so that will bring that area down to 30mm before we start thinking about bent rebar and other things. What are the downsides of reducing cover? I can think that at some point it will weaken the bond between the rebar and the concrete if it get too close to the surface. Also water ingress rusting rebar may be more likely but the concrete sits on isoquick which is 200mm above ground level.

@JohnMo how would I calculate how much extra heat loss I would have if I tied my UFH to the lower layers of mesh rather than the upper? i have 250mm eps and 250mm concrete the lower layer will be at 70mm from the bottom and the upper layer will be 170mm from the bottom.

Why does it not matter if sheets or rods are placed next to each other in such a way that the concrete cannot completely encase each rod. Is it because the yield strength of the rod is below the amount of grip the rod has inside the concrete, even if it is not complete encased. The rod will stretch before the concrete loses grip?