Building a low wall over a Heave Precaution drainage channel

[ToughButterCup]

YettaNuther fine mess I've got myself into.....

And it was all going so well.  My first bit of block laying, my first bit of proper wall backfill. Feeling right pleased with myself until I came to continuing the wall round the corner  ....

Here's my wall - the bit that works

 

 

Next job.... get the wall to go round a corner. How hard can that be ( to quote @Construction Channel )  ?

 

Here's the job ... marked out in yellow

 

And here's the twist .....  see the red iron bar stuck in the ground? Well it took next to no effort to get it that deep. (600mm)

Why?

Because the iron bar disappeared into the Heave Prevention drainage channel. And that's just (200mm)  below where I was planning to put the wall.

Oh how I wish I'd taken @jack's advice and taken many more photos during the build.

 

My question is :  which of the five options below should  I take - 

 

Compact the earth as normal and then 

• lay the foundations as before and build over the top of the channel (the wall is only four courses high - light as a feather) ?
• as above but put rebar in the foundation ?
• make the foundation wider than the drainage channel ( by -say- 500mm) ?
• avoid building over the drain (by moving the wall either closer to the house or further away) ?
• knock the house down and start again?

 

I tell you I felt like taking the fourth option once or twice recently.😑

 

 

 

[ProDave]

Build the footings either side of the channel, and bridge the gap over the channel with reinforced concrete lintels.  Build wall off the lintels.  Why make it difficult?

[ToughButterCup]

Ugh..... How stoopid can I be?

Actually the right question is - how knackered can I be?

 

Thanks very much @ProDave

 

 

[saveasteading]

How wide is the channel you are jumping over?

Is there an earlier discussion about this channel? It's my subject but that is a new term and concept  to me.

[ToughButterCup]

Ah, glad it's you @saveasteading ...

It's a 400mm wide trench with a standard perforated pipe in it. Covered with inch stone. It runs all the way round the house and discharges to a fairly steep bank. It works well. Or did when I last looked. SWMBO has covered the bank with greenery.

 

I'm told its purpose is to prevent frost heave and is standard in all new houses. 

 

I'll have a look and see if I've got any photographs of it during the building of the foundation.

[saveasteading]

4 hours ago, ToughButterCup said:

400mm wide trench

 

No bigger than a drain entry detail into the house, where precast lintels are the norm

 

4 hours ago, ToughButterCup said:

standard in all new houses. 

 

Dewatering the ground as standard? To make clay permanently dry, so it shrinks once and stays shrunk?    Hmmmmm.

Most houses won't have a handy ditch, and it would be a very bad thing to send more rain quickly to drains and watercourses. 

 

I just googled heave protection drainage channel and your original post comes up number 2.....in the whole world.

[ToughButterCup]

7 hours ago, saveasteading said:

.... 

I just googled heave protection drainage channel and your original post comes up number 2.....in the whole world.

 

Well I've got it wrong then haven't I... Nowt new about that. I'll dig out the plans and post them here. I bet I've got the terminology wrong, rather than the drain being  a construction error.