Lessons Learned

[LA3222]

just a quick post to share some of my issues which in hindsight are entirely self inflicted, hopefully this will help others not to make the same mistakes.

 

1. Put your waterpipe in the duct from the outset, soo much easier than pulling it through later. (I did consider it but dismissed it as wasn't sure exactly where my duct was going to come up at the time) - don't be like me!

 

I tried pushing 30 odd metres of mdpe through a 63mm duct, got 25m through then nothing. I dug two holes to find it, ended up having to attach rope to car - not gonna lie, it was a griz and I was hating life. 

 

2. When laying your hardcore sub-base for an insulated slab do the foul drain runs at the same time.

 

I was under time pressure to get ready for concrete so I just left stubs poking out to connect to later - dont do it, I've made life so much harder for myself having to dig through hardcore to do it.

 

3. If you ignore no.2 and just leave stubs make sure you leave a good length - i didn't! The stubs i left only just poke out from under the slab, god only knows why I did this. I have spent all day yesterday and today digging them out so I can put an extension length on to bring them out to roughly where the ICs will be. Digging through the hardcore really sucks ass. Yesterday wasnt too bad, today was on another level. The trench kept collapsing in on itself and my 600mm trench ended up about 1.5m wide - a very bad day today. Dont be a plonker like me.

 

I've made other rookie errors so far but fairly painless. These have been a right PITA.

[SuperJohnG]

@LA3222 I had a proper lol  there at the car thing. I hope you took pics? 

 

Ona serious note thanks for taking the time out to share this stuff its mega appreciated. Hoping to get on with my insulated slab in the next few months. 

 

On number 2 do you mean do the full runs? Was it digging through the part outside the foundations (scaffold area) that was hard?

[LA3222]

17 minutes ago, SuperJohnG said:

@LA3222 I had a proper lol  there at the car thing. I hope you took pics? 

 

Ona serious note thanks for taking the time out to share this stuff its mega appreciated. Hoping to get on with my insulated slab in the next few months. 

 

On number 2 do you mean do the full runs? Was it digging through the part outside the foundations (scaffold area) that was hard?

I wish I had taken pics, I seem to be doing a poor job of that lately as I keep checking stuff only to find i havent got a pic.

 

The clutch on my car lost a few yrs that day, who knew it would be so hard. The best bit is that pulling it like that cut through my duct chamber like a hot knife through butter which then created an additional repair task for me!

 

By full runs i mean put the whole lot in, pipes and Chambers all connected up. I wish i had done this at the time. I have a manhole on site to connect in to but I didn't lay any of it. I basically put the three downpipes in that go through/under the slab and then brought it out beyond where I thought my slab would be. The problem is that I misjudged where the slab would end and so had next to nothing coming out beyond the slab so I've spent the last couple of days trying to get to make them longer but at the same time not bring the house down by undermining it - not a fun game. 

 

I think my mistake happened because the lines I had sprayed on the hardcore at the time represented the outside of the timber frame/concrete slab but there was an additional 350mm on that for the cavity and toebeam which I didn't consider so it messed up where I'd put the pipes. I should have just put a good 2 or 3m on them.

 

Another problem was finding the damn things. I had marked an x on the kore insulation where they were but still struggled to find the things. I've certainly made this far harder than it needed to have been.

 

You can see in the pics how the trench started and how it ended - not good!

Edited September 5, 2020 by LA3222

[Pete]

1 hour ago, LA3222 said:

just a quick post to share some of my issues which in hindsight are entirely self inflicted, hopefully this will help others not to make the same mistakes.

 

1. Put your waterpipe in the duct from the outset, soo much easier than pulling it through later. (I did consider it but dismissed it as wasn't sure exactly where my duct was going to come up at the time) - don't be like me!

 

I tried pushing 30 odd metres of mdpe through a 63mm duct, got 25m through then nothing. I dug two holes to find it, ended up having to attach rope to car - not gonna lie, it was a griz and I was hating life. 

 

2. When laying your hardcore sub-base for an insulated slab do the foul drain runs at the same time.

 

I was under time pressure to get ready for concrete so I just left stubs poking out to connect to later - dont do it, I've made life so much harder for myself having to dig through hardcore to do it.

 

3. If you ignore no.2 and just leave stubs make sure you leave a good length - i didn't! The stubs i left only just poke out from under the slab, god only knows why I did this. I have spent all day yesterday and today digging them out so I can put an extension length on to bring them out to roughly where the ICs will be. Digging through the hardcore really sucks ass. Yesterday wasnt too bad, today was on another level. The trench kept collapsing in on itself and my 600mm trench ended up about 1.5m wide - a very bad day today. Dont be a plonker like me.

 

I've made other rookie errors so far but fairly painless. These have been a right PITA.

I feel your pain but we did our waste pipes the same as you but terminated a metre from the house and put 3 x 2 vertically so it just stuck out of the ground a little bit.

We put 100mm duct in for the water so it was easier to pull the 32mm pipe through. I am offering examples of how we did it to help people, we made plenty of other mistakes I can assure you!

[LA3222]

3 minutes ago, Pete said:

I feel your pain but we did our waste pipes the same as you but terminated a metre from the house and put 3 x 2 vertically so it just stuck out the ground

when I was cursing myself about what I'd done this was a thought that occurred to me.as to how I should have done it is put a 90 degree bend on the end with a stub poking up out the ground much like your timber example.

[Pete]

7 minutes ago, LA3222 said:

when I was cursing myself about what I'd done this was a thought that occurred to me.as to how I should have done it is put a 90 degree bend on the end with a stub poking up out the ground much like your timber example.

I have had thoughts like that on numerous occasions, hindsight is a wonderful thing. 

[SuperJohnG]

1 hour ago, Pete said:

I have had thoughts like that on numerous occasions, hindsight is a wonderful thing. 

Sharing those thoughts are great though and will benefit the rest of us.

[Ferdinand]

Thanks for the feedback @LA3222

[LA3222]

Figured I'd update this a bit, foul drainage is all in now, was a PITA but its done.

 

Next lesson - put your land drain in whilst the sub base is getting laid. I didnt?‍♂️ and yes it was another PITA job. To be honest I was thinking not to bother as my sub-base sits on sandstone which drains rapid, no groundwater to worry about so I figured whats it needed for? Quick chat with the SE and I find they include them by default and are reluctant to dispense with them regardless of ground conditions - something about the potential for frost heave. So, dig a hole and put some in?‍♂️

 

Another suggestion, if you know where your soakaway is going to be maybe get it put in whilst doing groundworks for foundations so its ready to connect to once gutters done. With the way my plot is it would have been far easier for me if I had planned this in. I had a 20T excavator on site for the sub-base, would have got the job nipped rapid, now have a 3T digger and not so quick/easy a job?