matthyde83

Unfortunately yes paid. Really not happy but at a loss as what to do if he won’t respond really. We’re now at the point where some steels are on site and up so I need some questions answered asap…

We are now well into our build and I’m having some issues with the structural engineer. I have some questions around locations of beams and possible alternatives and I cannot get him to respond to emails or phone. He was recommended by my architect but has apparently taken offence to my questions and now won’t respond at all. We don’t have final calculations and some of what was in the initial calculations simply doesn’t make sense! Help! Do I bite the bullet and go for a second opinion (probably at a reasonable cost). If so who, any recommendations??

If only - appointed by the warranty (self build zone) so does warranty and BC. At the minute to get him there I have to book 2-3 weeks in advance which is an absolute nightmare too! We have three doors on the back. 2x French doors where the cill is above floor height and 1x sliders that are level threshold. DPC comes vertical down cavity and under door before stepping the other side. Sliders have built in drainage on outside. Terrace sloping away for c.5m. DPC is 2 bricks above threshold.

Yep fully agree with all of your points. I think our DPM 1 achieves point 2, assuming we only put ties above that level (we’re quite high with DPC due to terrace at rear being level threshold - so first ties will be three blocks up). Point 1 I agree with but I had that debate with BC and he was extremely persistent that it needed to go in. We then had a debate about the Marmox blocks that he told me were pointless. So that was nice too. I particularly like it when he asked me what ventilation I was having in addition to MVHR!!!!

I cannot see why we need 2 DPM’s though. Only thing I think is we were talking about how do we get wall ties in and that’s when he said

Yep I found that. That’s the standard dealing with rising water. there’s then one below dealing with water ingress from outside

problem is that would be drilling through the DPM that’s lapped up the outside of the inside leaf. made the call to remove the paving slabs on top of DPC, that way we have 50mm to join cavity tray to DPC then bed the slabs on top.

The additional problem I have is how do I get the thermabeads injected in under the cavity tray without piercing the DPM. They’ll need to be injected from the outside so drilled through outside brick and the paving slab which I’m sure the installers are going to love me for!

I drew this last night. This is what they’re asking for. Atm the cavity tray isn’t in, we’re up to plinth brick height on the exterior skin and have the Marmox blocks in on interior. Obviously no insulation and screed yet. This is a standard detail, at the back we’re level threshold so the garden will be two bricks higher, so there we’ve stepped the DPC up another two bricks so the cavity tray and DPM would effectively be two blocks higher than FFL

My favourite bit however is that we need 2 DPM’s. Have one under the slab that we will lap up the outside of interior wall. They want another under screed that also laps up to cavity tray. We have a level threshold at back so our cavity tray will effectively be block and half above FFL inside.

Nope. Just demanded there be a cavity tray. We haven’t done interior block work so they suggested taking out the mortar 5mm or so at DPC and beading a tray in with silicone there then tape to interior block at a higher level.

So revisiting this as I’ve now started on site. We dispensed with the cavity tray and planned for beads all the way down. Up to cill height on external brickwork and building control/warranty have come round and said we absolutely MUST have a cavity tray and they won’t do an off without. Help!

My understanding of these schemes is exactly that. Help to Buy etc aren’t really for people that could Buy previously. They’re to give access to those that can’t in the usual ways.

Yep 350mm will just mean 33mm is unsupported on the inside of the cavity rather than the beam being central that’s all. Not a problem I suppose.

That’s a thought. We actually have a balcony and are taking the doors up to ceiling level so the outside will be hidden by a joist running in front of it. Could therefore easily sandwhich something in there. Although it’s a 133 beam in a 100 wall…

My structural engineer isn’t the most helpful / available so I’d prefer to avoid asking him anything tbh!

Some advice required... I have a lintel across some sliding doors (4.3m). SE has specified 2x 203 133 UB 30 beams bolted at 600 centres. I'm having blown in EPS beads so its occurred to me that they will probably get in the gap (150mm cavity). How do you prevent thermal bridging here though, any better suggestions than letting the beads in! Surely the bolts and spacers will create a cold bridge?

yep ACIS…

There were there for less than 3 minutes… I should be pleased there are no issues I suppose but still, I’m in the wrong game $$$

how did you find the selfbuildzone warranty and bc? We’ve just poured foundations and had our first visit just before pour. To say I am underwhelmed would be an understatement…

how do you achieve 400mm?

brick and block, 2 storey, hipped with 6 dormers

Hmmmm... builder said he thought 36 tonnes. My estimate is showing 168 bags of cement and 18 bulk bags of building sand. Doesn't add up to 36 tonnes does it? Building 5 bed detached, 250sqm ish. Will look into tubs.

Doing some ringing around I think you're right!

Estimates are calculating we need about 36 tonnes of mortar for our whole build. Builder has recommended looking into a mortar silo rather than mixing on site. thoughts??