"Bird's nest my ****"

Entry posted by Nelliekins December 29, 2018

1237 views

Waiting isn't something I am known for. Waiting nearly 3 months, for these mythical birds to vacate the invisible nest isn't going to happen.

4 weeks later and we're into July, and I've had enough. Here's what was left of the hedgerow, along with my weapon du jour.

As it happens, there was no nest in the hedgerow. Probably because the houses all around have cats that hunt, and even birds aren't stupid enough to nest 4 feet off the ground when there are dozens of suitable nesting places in the trees on both sides of the street! The closest thing I found to a nest was a 20-year-old gin bottle, filled with cobwebs. We also chopped down about 50m2 of brambles and a few western red cedar that were in the middle of the plot. Then we put a bit of Heras-style fencing around. So now, our site looked a lot cleaner and larger:

But we had still waited too long. The firm we had verbally accepted a quote for the groundworks from had moved onto a large new job, and wouldn't be able to return to our project until the new year. ?

Time to find some new groundworkers... should be simple enough, right? Wrong. A big contractor had just pulled out of a major development project a few miles away, so every groundworks company within 20 miles had been signed up to take up the slack. We looked at everyone from "one man with a digger" to big national outfits, but nobody was able to take the job on. Until we found this company, based in Liverpool. Smallish outfit of about 15 men and a couple of decent-sized machines, including a shiny new 13 tonne excavator. After some to-ing and fro-ing, we decided to take them on, on a day rate basis.

Planning passed (way after the expected date, but that's nothing new with our LPA apparently) - both applications. So Kim chose the big kitchen layout. But before we could break ground, we needed structural calcs done, and that meant an engineer!

After ringing around quite a bit, we found a local firm that were happy to take the job on. They didn't have much ICF experience, but I figured that it wouldn't really matter. How wrong I was...

This engineer started off on the right track, working out slab details from the borehole results, etc, etc. Then it came to the ICF lintel and column calculations. Now, the new kitchen design incorporated some 6m-wide bifold doors across the back of the house, with 1m-wide columns either side of the bifolds. We had picked Logix as our ICF product of choice (primarily price driven, but also because we could have thicker external wall insulation, which would improve our thermal performance considerably).

The Logix blocks were 406mm high, and had plastic webs for supporting horizontal rebar at roughly 1/4 and 3/4 of the height of the block. Here's a pic:

So far so good. Except our engineer had decided that the steel would be placed every 150mm vertically in the wall for the columns either side of the bifolds. Now, for the layperson, I'll point out why that doesn't work. Here's the list of positions for the steel vertically, in mm:

- 150, 300, 450, 600, 750, 900, 1050, 1200, 1350, 1500, 1650, 1800, 1950, 2100, 2250, 2400, 2550, 2700

Now here are the positions where the rebar is supposed to sit:

- 100, 303, 506, 709, 912, 1115, 1318, 1521, 1724, 1927, 2130, 2333, 2536, 2739

Notice the numbers in BOLD in both lists? That's where the web would physically get in the way of the steel rebar. Cutting the webs would destroy their structural integrity completely, and mean you have to find alternative ways of bracing the ICF wall blocks - which would be possible if they weren't corner blocks. Which they were.

I pointed this out to the SE. He said I didn't know what I was talking about. So I had my ICF expert builder (who agreed with me about not cutting those webs) come and chat with the SE, and explain the same thing. The SE smiled, and said that it would be fine. So I had the ICF block manufacturers (who also agreed with me about not cutting those webs) ring and email the SE.

The next thing I know, the SE has emailed me, saying (and I quote, here);

Quote

I cannot work with you under these circumstances so I therefore withdraw my services and recommend you find another Engineer who can satisfy your demands.

Any of the information you have received to date is our property and should not be used in any way otherwise we will have to take legal action.

The fact that we couldn't use his designs, because they were inherently unworkable, was the problem in the first place!

Lesson learned - do NOT engage a structural engineer who doesn't have experience with ICF when you're building an ICF house. 8 weeks we had been working with this engineer, and all for nowt.

Phoned a couple of ICF manufacturers for recommendations for an SE with ICF experience - there was 1 common name on the 2 lists I received back. I phoned him, and accepted his quote the same day. 4 days (not weeks) later, I had the calcs in my Inbox, and an invoice to be paid. The steel was in the right places for the blocks we were using, and we even had little detailed drawings showing how to tie the lintel links to the main rebar, and where we had to put what types of welds & bolts to bring everything together properly.

Maybe our fortune was changing for the better at last...?