Taping the joints between magnesium boards

The fiberglass tape to put over the joints between boards to prevent the plaster from cracking along the joint.

Taping the joints

Also completed is the boarding on the study ceiling.

Also now dry is the plaster test panel in bedroom 4.

First floor insulation

The first floor void is being insulated with warncel - recycled newspaper.  3/4 of it will be insulated about 100mm deep tipped in from above, the other 1/4 will be the full depth of the floor and will be 'injected' in with a hose from below.  The first bit of the floor to be insulated from the top is here, so we can finish the bottom of the clay plaster panel (just about visible in the background).

The bags of Warmcel insulation.

Tipping the warmcel in...

The insulation between the joists.

Priming the magnesium board

The magnesium boards are quite smooth (even on the rough side) and they don't give much of a key for the clay / lime plaster to adhere to.  To improve this we are priming the boards with DG27 which leaves a gritty surface.

Test panel of a clay top coat

This panel in bedroom 4 has a Womerseleys (ionic) antique white clay top coat applied.  The white magnesium board gives you an idea of the colour of the clay.  The idea is that you would not paint this, it is left as it is.

More plaster and magnesium board

The first coat of plaster applied to the wall in bedroom 2, except along the bottom. We need to permanently fix the ply floor down to fix the timber stop that we will plaster down to, we will do this once we have insulated the floor void.

Magnesium board completed in bedroom 4.

Plaster in bedroom 4 nearly dried out

Clay on the gable wall in bedroom 4 is drying out well.

More clay in bedroom 2

Plastering over the reed mat over the window.  The reed mat does feel springy to plaster onto but we are hoping that after the first coat has gone off the background will stiffen up and make it easier to apply subsequent coats.

A bit more plaster applied to the wall in bedroom 2.

Clay plaster and reed mat

Starting the first coat of clay plaster in bedroom 2.

Over the window we have hemp and lime insulation rather than straw, which is set back from the straw.  Here we have used some reed mat to plaster onto.  The timber round the window that we are going to plaster over has been primed with DG27.

A close up of the reed mat over the window.

More boarding and clay tests

So far we have sealed the air barrier in the FF ceiling to the first coat of clay plaster, by priming the clay and sticking it with a proprietary tape.  However when we came to do the subsequent coat of clay plaster yesterday it was more difficult to get the clay to take to the membrane, particularly when there was a reasonably large lap.  We did manage and think it will be fine, however we wanted to see if there was a better way of doing it.  Here we have cut the lap down to about 50mm, which you can see sticking out from behind the magnesium board on the ceiling.  We didn't prime the membrane with anything this time and just plastered straight over it.  This seemed to work much better and we could squeeze a bit of the clay plaster up behind the ceiling board which also helped.  We will probably carry on with this method now as it is easier to deal with the membrane in the first coat of clay, so don't have to think about it on the levelling coat of plaster.

We're still carrying on with the mangnesium board on the ceilings.

We have also started putting up the door architraves in places as we are going to plaster up to them, rather than apply them over the finished plaster.  The architraves will be painted an offwhite to match the plaster colour.  We will probably put the first coat on before plastering and then a finish coat after the plaster.

Second coat of clay plaster

Onto the straw bales we first put a slip coat of clay (very wet and sprayed on), we followed this with a base coat of clay plaster some time ago.  Today we are working on the next coat of clay on the straw.  This panel in bedroom 4 is now reasonably level (it is all relative on straw!)  A thank you to Graham for his help today with the clay.

The previous coat of clay needs to be wet down first, before applying the plaster which we did with this hand spray.

The gable wall in bedroom 4 is a much larger area and as it is constructed with custom made 'triangular' bales, it has turned out more uneven than elsewhere.  The second coat of clay plaster has been applied here but there are still some areas which may need more leveling.  We are not trying to get the straw bales completely flat, we want to retain some of the character of the straw in contrast to the flat studwork internal walls, but there are some spots which are a bit too characterful!  When we put the first coat of clay plaster on (after the slip coat) I don't think we took out enough of the unevenness, so in the future we will bear this in mind!

This is a white clay top coat from Womersleys, which we are testing out for the top coat.  It is self coloured and comes in a range of different colours.  This is the antique white, however with clays the whites are more buff than white.  The plaster is made up using white clay, white sand and casein.  Casein are proteins from milk which are used to help bind the plaster - white clay does not bind as well on its own as grey clay.  The casein gives the plaster a particular smell when wet (it goes when dry).  The plaster is supplied dry in a powder which you add water to, and I would not advise keeping any mixed up plaster as the smell gets quite intense!  The plaster also contains a very small amount of titanium dioxide as a pigment to increase the whiteness.  Womersleys sell natural and sustainable building products and are very responsible with the by-products of the titanium dioxide which they use to make other products they sell.

Door frames

A couple more door frames put in upstairs to Bedroom 4 and the family bathroom.

More magnesium board (there is going to be a lot of this!)

Starting from the straw wall we are begining to put up the magnesium board in bedroom 2.

At the same time we are progressing the magnesium board on the walls in bedroom 4 (ready for our plaster test).

The first door lining fitted

The first door lining fitted to the downstairs WC.  This is one of the rooms we are going to use as a test for the plaster so we are progressing this first, along with bedroom 4.

Clay plaster in bedroom 4

The first coat of clay plaster (after the slip coat)  on the wall in bedroom 4 is now complete.

Boarding the ceiling in bedroom 2

The magnesium board complete on the ceiling in bedroom 2.

Battening out the rooflight in bedroom 2 ready for the magnesium board.  

The rooflight boarded out with magnesium board.

Clay plaster in bedroom 4

The first coat (of probably 3) of clay plaster goes onto the straw wall.

The timber to the side of the window is painted with DG27, to make the surface more 'gritty' and give the clay a better key.

We then plastered in some hessian (we have a lot of this on site!) to prevent the plaster cracking over the change in substrate from straw to timber.

Second electricity reading

The second week of the heat pumps life has just been completed and this week it used 30kWh (approx £4.50) of electricity to run- looking good!

Magnesium board

The stack of magnesium board to be used to board the ground floor ceiling and to try on the walls in our two test plaster rooms (Bedroom 4 and the downstairs WC).

First up is the ceiling in bedroom 4.  When we did the first bit of magnesium board a while ago on the floors in the bathrooms we were using a jigsaw to cut the boards with.  While this worked well it was blunting the jigsaw blades very fast.  This time we tried the score and snap method recommended by Resistant (the board manufacturer).  This works well and assuming you can score accurately makes a neat precise cut.

Making progress... nearly complete!