SUBTERRANEAN SANDWICH

Footlong or mini sub?  This week our builder is focusing on making a sandwich of epic proportions, a veritable monster ‘Scooby Snack’ made up of lots of different layers all contributing to the extension floor.  In this sweltering heat, making a sandwich saps all the energy I’ve got to rustle up a meal in the kitchen so carefully laying down each course in the blazing sun must have taken a superhuman effort.

 

Making a construction 'Scooby Snack'

But back to our subterranean sandwich.  First a layer of crushed hardcore is laid to cover the earthy ground following by a liberal coating of sand, beaten into submission with something called a ‘wacker’ which sounds like something you might find on the shelves of an BDSM store or in an Ann Summers catalogue.  (Oooh, er missus!)

 

First a layer of 'wacked' hardcore

Then a wonderfully dark, rubbery membrane to sit on top like a layer of rich, velvety chocolate cake covering albeit somewhat chewier than the real thing.  Please don’t try eating rubber membrane even if it is low calorie!

 

Followed by some DPM - damp proof membrane

Just look at those wonderful hospital corners.  I tried to get my pond liner to look like this but it was nowhere near as neat or tidy.  I just wish I could fill the whole thing up with water and go for an afternoon swim!

 

The perfect corner fold

After the rubbery layer comes a generous dollop of concrete followed by a lovely thick slab of EcoTherm, the construction equivalent of halloumi cheese but with greater thermal properties.  It’s a good 4 inches thick which is how I like my cheese sandwiches but at £60 a sheet, a darn sight more expensive.

Add a layer of concrete

 

Topped with 4 inch thick EcoTherm

To keep in the heat

On top of the EcoTherm, there’ll be another generous dollop of concrete to seal in the flavour.  Mmm, this tasty construction sandwich should ensure your floor remains snug and toasty, locking in all that lovely heat thus saving you a few quid on the energy bill. 

So, at the end of week 3 not only do I have my very own ‘henge’ to help me celebrate the longest day but I also have a solid subterranean sandwich making up the middle of the extension.

Chi Henge