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Sunday 28 October 2012

Day 1 - no turning back!


This is Old Lawns Farmhouse as you will never see it again. Today is the first day of what will be a lengthy project with an unknown ending! 

Having decided to stay put in our old Shropshire farmhouse for the foreseeable future, our thoughts then turned to what work should be done to secure and preserve it for the future. Like many old houses with solid walls Old Lawns Farmhouse (from now on known as OLF to save my typing fingers) was rendered with a thick coat of cement render, probably sometime in the 1960's. Intended as a means of weatherproofing, this cement based render in fact causes old houses like OLF to slowly degenerate by locking in the moisture which inevitable finds its way in via cracks in the render over the years. The walls of these old houses were intended to breath, absorbing moisture and allowing it to evaporate back into the atmosphere. The use of natural materials like lime plaster inside and lime mortars between the bricks and stones in the walls meant that this breathing could take place. Smothered by cement render on the outside and gypsum plaster on the indside, this breathing stops and the building starts to slowly suffocate. Any moisture finding its way into the wall from outside is trapped and has only one place to go - into the house, causing damp patches and helping to raise the internal humidity, resulting in condensation in the corners of rooms (low down near the floor), lifted internal plaster and flaking paintwork. Water vapour generated internally, by kitchens and bathrooms and people breathing(!) is also trapped inside the building and adds to the humid indoor climate.

You can read more about all these issues at www.heritage-house.org which was the place that eventually convinced us that we should take action to save OLF. Following a visit by Pete Ward of Heritage House Ltd in early October 2012, we decided that the first step in renovating OLF will be the removal of the external cement render on the ENTIRE house. Depending on the condition of the brickwork and stonework underneath we will then decide what to do next. There are a few options:

  • Clean the brick surfaces and repoint with lime mortar. Possibly paint the re-pointed brickwork with a breathable clay based paint if the decorative appearance is not too attractive.
  • Repoint with lime mortar and re-render but this time using lime render which will allow the walls to breathe.
  • Apply a breathable external insulation layer and re-render on top of that with lime render.
These options get progressively more expensive but the decision of which route to take will mainly be made based on the cosmetic and structural condition of the brick/stonework once it is revealed. Which takes us to the second post in this blog - what lies beneath!!?

What lies beneath?

Having received the report on OLF, I was inspired to pick up my lump hammer and chisel and start whacking the cement render on the lean-to at the east side of the house. Although we will need the experts to do the vast majority of the work, hacking off render is something I can manage- it just takes time and energy. I'll be taking off as much as I can on the lower portions of the building and let the professionals tackle the parts which I can't reach. We have also decided that the west wall, which is the only stone wall, will be gradually worked on, removing render and re-pointing with lime render bit by bit. This way we can check on the structural integrity of the wall as we go as its likely that this wall could be full of "holes" where old mortar and stones have shifted over the years. This means that this will be a job for next spring/summer since lime mortars can't be used in the colder temperatures of a Shropshire winter.

And so to work on the lean-to with the hammer and chisel! Here are some shots of the progress made today.
I started at the south east corner and this came away very easily in big lumps. Most of the cement render was visibly wet and clearly trapping water in this corner of the wall. Even at the top of this wall just to the left of the window, the lime mortar between the bricks was wet beneath the cement render. So this is not "rising damp" as it is about 1.5 metres up the wall!! This is water trapped inside the wall by an impermeanble coating of cement!
This is some of the wet lime mortar - after a couple of hours in the open air it was already visibly dryer after years of being permanently wet. You can see how it has eroded away due to the permanent moisture in the wall.


Now you see it! 

So the hacking continued, revealing that the wall was considerably dryer away from the SE corner. This east facing aspect is one of the more sheltered sides of OLF which explains why the wall was dryer, the further away I got from the SE corner.

And finally after just 2.5 hours of work all the render is removed from the lean-to and the renovation of OLF has started in earnest.
Now you dont! 


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