Monday, March 21, 2011

Alchemy, Stone and Cement

As a student many years ago, I worked the summers for a concrete repair company, Remcrete from Hitchin, Hertfordshire. We would pile in the back of the van and head of into the wilds of East Anglia to mend things with concrete. Our specialities were bridges and cellars. 
Old metal reinforced concrete is prone to spalling', where water get into the steel and causes rust, which causes the concrete to crack, and you see the characteristic rusty stains, which lead to structural decay. 
The Remcrete remedy is to hack out the damage and replace it with epoxy resin and concrete - tracking out dead concrete using a hand held Kangol hammer whilst hanging off the side of a bridge is no fun, but it works a trick!

In a cellar in Stilton, we fixed a running water leak by adding a special treatment to concrete to make it set water tight in seconds - literally plugging a leak in an instant

Well, this long distant other life came in useful for the new Turnip house, as we found just such a 'spring' as we excavated the floor:

unwanted water!
I remembered the name, sort of, and thanks to  the wonders of Google the magic formulation was found:

Sika 4a
 This will set concrete in 15 seconds - don't loose your glove! 
And it did the trick - no more water out of the wall.

Today, another perennial problem - how to fix wood to a soft stone wall. I employed the traditional method of putting a wooden plug into a small hole (hopefully) and then fixing to that.

The quick setting cement formula was perfect for cementing in the plug.

we're going to keep the dpc up the wall just in case, and fix panelling to the batten.
there's a piece of pressure treated fence post buried in the wall to hold the batten - with magic cement to hold it!

more conventional wall plug fixture - where possible. This is a remade piece of windowsill

the even more traditional 'wedge' (or bodge) fixing!

looks pretty crude, but on this all else (literally) hangs!


We did not see the supermoon last night, but at just past it's perigee tonight, it still looks pretty great:

the 2011 March full moon falls on the same date as perigee – the moon’s closest point to Earth for the month. At perigee yesterday, the moon lay only 356,575 kilometers (221,575 miles) away.
(thanks to