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Onward and upward!

Nelliekins

Entry posted by Nelliekins

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So, our ground floor walls are up, and ready for a concrete pour... almost! Despite our use of Logix ICF blocks, I had fallen in love with the simplicity of the joist hangers used by NUDURA. Essentially, all you do is slot metal plates through slits in the ICF blocks, hook them onto a bit of rebar in the wall, and pour the concrete. Then you wrap the end of your joists in a folded metal U-plate, and put tek-screws through the metal plates, through the U plate and into the joist. The shear strength of the metal plates and the tek-screws is what holds the joists up. So, before the pour, you end up with this:

 

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Some people choose to put battens under the joist hanger plates before the pour to stop them moving during. We didn't bother, because the steel rebar was holding them fairly well anyway, although most of them were also screwed to the blocks (we'd finagled the joist spacing to fit the stupid imperial measurements of the Logix blocks, which meant at least one plate for each joist was able to be screwed to a web in the ICF.

 

So, the pour was uneventful in the end, apart from one tiny issue. Under that lovely 45-degree wall at the back of the garage, the block and beam floor was running under the angled wall. Which should be fine, but there must have been a small gap between the blocks somehow. After about 5 minutes of pouring concrete into the internal wall, we were getting a bit confused as to why the concrete level wasn't rising...

 

... It transpired that a 7N concrete block was now floating inside the wall, and the concrete was pouring through the resulting gap and under the block & beam floor in the garage, filling the void beneath. ? We only realised how far it had flowed under the garage when we started lifting floor blocks. In total, in those 5 minutes, we'd poured just under 3m3 of concrete into the void beneath the garage floor - the void had reduced from an average 750mm height to under 150mm in places! On the plus side, at least it didn't fill the void completely, given we still have to run services under there!

 

Here's a photo showing how much it filled up:

 

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Still, the garage walls aren't going to shift anywhere now! And it only cost £300 in spilt concrete...

 

Anyway, the rest of the pour went really well - no big bows (that we could see) and no bursts, despite all of the silly joints we had. Even little bits of PU foam seemed to withhold the weight of the concrete:

 

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(No, the string isn't supposed to be tight to the blocks - it was set so that a piece of CLS fit perfectly behind. And yes, that upright should have been screwed to the ICF blocks... except the observant among you will have noticed the webs don't line up between the courses. This was a deliberate decision made by me because of an alignment problem with the joist hangers above the bifold opening, and this seemed to fix it)

 

So, concrete poured, and walls looking good:

 

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The internal walls (garage, kitchen and stairwell) were kept 1 course lower so that they could act as a bearing surface for our upstairs floor joists. Seemed like a good idea to me, anyway!

 

Time for another ICF delivery...

 

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The big RSJ is for the 6m span between kitchen wall and garage wall, and will carry the load of the first floor joists in the middle 1/3 of the house. All well and good, but the massive trees at the front meant that getting a crane on site wasn't going to happen, and the cost of a crane that could clear the trees from the street was more than a little prohibitive... Time for some back-breaking lifting, because that beam weighs more than 1/4 of a tonne!

 

Some swearing, and the death of a couple of ratchet straps, and the beam was lifted up into place...

 

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And the length was perfect - we had less than 10mm tolerance once you allow for the required bearing on the concrete walls! Timbers sailed past the end at the garage - I was too lazy to cut them at the time (and that came laziness back to bite me on the ar$e later in the build!)

 

Say hello to the front of the house! Hallway window, nice doorway and the integral garage all present and correct

 

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Before we can carry on building the walls, we need to put the floor joists up and get a floor deck down:

 

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And time to start boarding it out:

 

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Which would have been easy if it weren't for the fact that the tolerances on the board joints wasn't so woeful:

 

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These boards were in the same pack, and the tongues varied by over 3mm. Biggest tongue we found across the lot was 20mm, and the smallest was 12mm. This meant we had to try mix-and-match for the floorboards, which took days longer than it should have... ?

 

Nevertheless, 7 days later, and we had the floor down, and were building walls again. 3 more days, and we were cooking on gas - first floor walls were 2/3 up and we were erecting the bracing again:

 

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Time to put some lintels in for the windows (you can see the ICF cavity closer under the rebar links):

 

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It was at this point that we realised we had a bit of a problem... our house was too tall! Our planning permission showed a street scene, which had the ridge line of our house lower than next door's house. The drawing had been produced by asking the neighbour to measure the height of his eaves when he was clearing out a gutter - he'd used a tape measure, so I had no reason to doubt his figures...

 

...But we were out by nearly 600mm on the height. I had to go back one night, and put a laser on a staff, just to see how bad it was. Here's the picture, showing the laser line from the top of a 2.4m staff, shining on the neighbour's chimney:

 

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The upshot of this was a third planning application, and lots of sleepless nights, because we had to get a height increase approved (we first tried to use a minor non-material amendment, only to be told by the LPA Planning Services Manager that "a minor non-material amendment was not appropriate for securing an increase in height"... only to find out that the same Planning Services Manager had personally approved an increase in height on Chorley Nissan's planning application using a MNMA only 10 months prior! I wonder who had a nice Christmas present from Chorley Nissan that year?)

 

Still, while we waited for approval (so that we could order the roof trusses) we could crack on with bracing up the first floor openings. And we had a ground floor that was giving us a sense of what it'd be like when it was finished:

 

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We were old hands at bracing openings now, having done it for the previous 2 floors of the house!

 

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Anyone else think it looks like something from an early 80s arcade game?

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Thedreamer

Yup, I can see the arcade look.

 

Last picture looks a bit like a face. A friendly face.

 

The build is looking good, is that you nearly up to date?

 

 

 

 

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Nelliekins
31 minutes ago, Thedreamer said:

Yup, I can see the arcade look.

 

Last picture looks a bit like a face. A friendly face.

 

The build is looking good, is that you nearly up to date?

 

Not yet! That's late spring covered, next up is summer 2018, and the roof going on and windows going in! 

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Ferdinand

WHatw as the actual situation on that roof.

 

Was it actually built too high, or did the street view give a misleading impression.

 

IF the latter, calling it "an illustrative street view" may have saved you.

 

Ferdinand

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Nelliekins
3 hours ago, Ferdinand said:

WHatw as the actual situation on that roof.

 

Was it actually built too high, or did the street view give a misleading impression.

 

IF the latter, calling it "an illustrative street view" may have saved you.

 

Ferdinand

 

As it happens, it was a bit of both. The setting out engineer had taken the wrong reference point for the setting out of the basement slab, testing the neighbour's DPC as ground level instead of 140mm up from ground level. But the bigger problem was the neighbour's "measuring" of their eaves height. 

 

Our solution was fairly simple - just reduce the pitch of our roof to accommodate the planners' desire for our ridge line to stay below the neighbouring houses. Our roof was never going to be converted because it was already too shallow, so dropping another 2 degrees of pitch from 27° to 25° wasn't a huge issue for us. I wouldn't have been able to stand up in the loft regardless. 

 

However, it did mean slightly less effective solar PV, especially in the winter months. Ho hum! 

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Mr Punter

Egger Protect is good quality flooring and I have never had problems with tolerances. Regarding the height issue it is well worth getting a topographic survey incorporating the neighbouring buildings and a setting out engineer so that you avoid these issues. Very good that they were not focused on eaves height!

 

Regarding PV we have sold a bungalow with a north facing shallow mono pitch roof and the purchaser had PV installed to the same pitch. Apparently it did not impact that much.

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Nelliekins
49 minutes ago, Mr Punter said:

Regarding the height issue it is well worth getting a topographic survey incorporating the neighbouring buildings and a setting out engineer so that you avoid these issues. Very good that they were not focused on eaves height!

 

That's the point - we had a topo done (cost £420) prior to completing the excavation of the basement hole - all setting out was then done by a setting out engineer (at a cost of £350) based off the topo. They just misread the topo somehow, because our only height datum was the DPC on the neighbour's house, and all the measurements were calculated using that as ground level (when clearly it wasn't).

 

By the time we realised the problem, we had concreted the ground floor walls and built the first floor walls up. Our choice was either to have lower ceilings on the first floor (and I am not a fan of low ceilings - the basement is over 9' and we're at 8'4" on the ground floor), alter the roof pitch, or get the planners to let us have a taller house than either side. I vetoed option [1], and we had had enough dealings with the planning dept at this point to know option [3] was unlikely, which only left option [2] - alter the roof pitch. It still required a new planning application, but because it was obvious why we were making the change, and because it was obvious we weren't trying to make space for a future loft conversion (it's only 1.4m clearance in the loft now), the planners were much more accommodating.

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Adam2

Thanks for the really informative blogging - I'm sure I'll be back to look in detail as we progress.

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Nelliekins
1 hour ago, Adam2 said:

Thanks for the really informative blogging - I'm sure I'll be back to look in detail as we progress.

 

To be honest, I'm glossing over some details somewhat!

 

For example, that 45-degree wall was interesting to brace, mainly because it wasn't exactly 45 degrees. After foaming the wall joints, I was wondering how to brace the wall properly. My builder-come-consultant had a genius idea. We ended up creating a hinged OSB screen (using a bunch of standard door hinges), so that we could form each of the angles independently. Then we screwed the OSB to the webs in the ICF blocks to make it solid. Then we put CLS timbers across the OSB, and bolted together, to give it more rigidity, and bolted the CLS timbers together. Worked a treat. You can see the detail in pictures 4 & 7 above.

 

Lifting the steel beam was a challenge, too. We attached ratchet straps around the uprights for the scaffold system (one in the kitchen side and one in the garage side, and clamped into the web with timbers), and then used spare ICF blocks from the basement walls as chocks to insert every time we got another 400mm up. That allowed us to adjust the straps safely each time, and start again. The problem came when we got to the last block - one ratchet snapped, and the beam dropped at the back. Thankfully we were (sensibly) working from above (on the scaffold) at that point, because if it had hit someone below we'd have needed an ambulance. The final 700mm of lifting for the back end of the beam was done by myself and 2 mates on our shoulders, once we had lifted the front end onto the garage wall and secured with metal strapping so it couldn't fall off. And boy, was it heavy!

 

Now that I am getting a bit of personal time back, I'll start trying to include more anecdotes like these in the blog - it's just been mental levels of stress the past few weeks (Dad in hospital 200 miles away, and my day job looking like it's about to end right when both mortgages are at their peaks...)

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