Hello all
I'm posting here for the first time after finding this site whilst researching various IWI systems. I'm fairly new to house renovation so I still have a way to go before I can worry about dusting!
I bought a small 2 bed cottage (former farm house) in rural mid Wales back in 2018 and I've been pootling about since then resolving the odd damp spot, removing external render, repointing the entire external walls etc etc.
This house is absolutely freezing in winter, after having double glazing finished last year I vainly hoped to see a big difference but in hindsight I was expecting too much given there is no central heating yet, just a single log burner downstairs and small portable oil filled rads in bedrooms. Even with the log burner running at full steam, I can see my breath just 2 metres away! So the internal walls are now back to bare brick in readiness. After some research I decided to opt for Ty Mawr's IWI system as follows:
3:1 mix of NHL3.5 > Shropshire sand/aggregate and reinforcing fibres as a levelling coat (I would have preferred NHL 2 but was advised against it as the board adhesive was NHL 3.5 anyway).
60mm Schneider Multitherm wood fibre boards fixed with Isovit lime and fixings
20mm boards for window reveals
2 coats of lime hemp, the first using jute scrim for edges etc, the 2nd coat mixed with a fine lime finishing plaster.
Now I've dwelled long and hard whether I'd be up to doing all this myself as plastering has always struck me as something I'd be hopeless at. Having had a couple of quotes which were eye watering I decided I'd have to go the DIY route. I considered 2 options, insulated plaster or boards, I opted for boards due to the superior thermal gains. And so here I am with 26 boards stacked in the kitchen, pallets of sand/lime in the garage and shiny new trowels at the ready. I decided yesterday to make a start and chose a small wall to the right side of the bedroom chimney as a good candidate......it did not go well.
The good points (in relative terms!)
* the product is still attached to the wall the following day
* I have improved the levels to within the +/- 5mm tolerance for the board fixing (but it's touch and go). I understand I can add adhesive to the wall as well as the board for any slightly deeper hollows.
The main issues I found were reluctance for the product to bond with the masonry and that by the time I had applied 3' sq, the product was becoming too stiff to put a feather edge over it
Now after repointing the external walls, I had learned that the bricks here are extremely porous. Ty Mawr's advice was to soak the wall the day before and then mist it again prior to starting, I know from my limited experience that if I soaked the wall a day before any work, the wall would have dried out already, especially in the recent hot spell. So I gave the wall a good spraying prior to starting up the mixer which I ran the first mix for probably 20-25 mins and a follow up spray before picking up the trowel. I assumed my issues were due to the mix being too dry but having rewatched a few Youtube vids, I'm not so sure.. Today brings new options, 1. call Samaritans 2. stay in bed in the foetal position and hope it was all a bad dream 3. Have another go on an even smaller wall and try a wetter mix to see if it would spread like butter as seen on the mentioned Youtube videos. So I put my overalls on and chose option 3, a slightly wetter mix was made and.........I delved into another episode of tourettes syndrome. Repeated queries to the Gods as to "WHY WON'T IT STICK"?!
The good point (in relative terms again)
* 4 hours later the product is still on the wall
* I did manage to achieve a more level finish with the trowel than on attempt 1...... it ends there
So I can only assume I'm not soaking the brickwork sufficiently? I came to this conclusion after noticing that when I misted a coarse of bricks and applied plaster straight after, it did seem to bond better.
I'd be grateful if anyone can suggest where I may be going wrong here, the mix was definitely at the correct sand/lime ratio and mixed for minimum 20 mins each time. 2m sq took me 45 mins+ after which I'm in no mind to start another mix! I've a lot more to do and it has to be finished before Autumn when I have a heat pump/central heating being installed.
Thanks in advance
I'm posting here for the first time after finding this site whilst researching various IWI systems. I'm fairly new to house renovation so I still have a way to go before I can worry about dusting!
I bought a small 2 bed cottage (former farm house) in rural mid Wales back in 2018 and I've been pootling about since then resolving the odd damp spot, removing external render, repointing the entire external walls etc etc.
This house is absolutely freezing in winter, after having double glazing finished last year I vainly hoped to see a big difference but in hindsight I was expecting too much given there is no central heating yet, just a single log burner downstairs and small portable oil filled rads in bedrooms. Even with the log burner running at full steam, I can see my breath just 2 metres away! So the internal walls are now back to bare brick in readiness. After some research I decided to opt for Ty Mawr's IWI system as follows:
3:1 mix of NHL3.5 > Shropshire sand/aggregate and reinforcing fibres as a levelling coat (I would have preferred NHL 2 but was advised against it as the board adhesive was NHL 3.5 anyway).
60mm Schneider Multitherm wood fibre boards fixed with Isovit lime and fixings
20mm boards for window reveals
2 coats of lime hemp, the first using jute scrim for edges etc, the 2nd coat mixed with a fine lime finishing plaster.
Now I've dwelled long and hard whether I'd be up to doing all this myself as plastering has always struck me as something I'd be hopeless at. Having had a couple of quotes which were eye watering I decided I'd have to go the DIY route. I considered 2 options, insulated plaster or boards, I opted for boards due to the superior thermal gains. And so here I am with 26 boards stacked in the kitchen, pallets of sand/lime in the garage and shiny new trowels at the ready. I decided yesterday to make a start and chose a small wall to the right side of the bedroom chimney as a good candidate......it did not go well.
The good points (in relative terms!)
* the product is still attached to the wall the following day
* I have improved the levels to within the +/- 5mm tolerance for the board fixing (but it's touch and go). I understand I can add adhesive to the wall as well as the board for any slightly deeper hollows.
The main issues I found were reluctance for the product to bond with the masonry and that by the time I had applied 3' sq, the product was becoming too stiff to put a feather edge over it
Now after repointing the external walls, I had learned that the bricks here are extremely porous. Ty Mawr's advice was to soak the wall the day before and then mist it again prior to starting, I know from my limited experience that if I soaked the wall a day before any work, the wall would have dried out already, especially in the recent hot spell. So I gave the wall a good spraying prior to starting up the mixer which I ran the first mix for probably 20-25 mins and a follow up spray before picking up the trowel. I assumed my issues were due to the mix being too dry but having rewatched a few Youtube vids, I'm not so sure.. Today brings new options, 1. call Samaritans 2. stay in bed in the foetal position and hope it was all a bad dream 3. Have another go on an even smaller wall and try a wetter mix to see if it would spread like butter as seen on the mentioned Youtube videos. So I put my overalls on and chose option 3, a slightly wetter mix was made and.........I delved into another episode of tourettes syndrome. Repeated queries to the Gods as to "WHY WON'T IT STICK"?!
The good point (in relative terms again)
* 4 hours later the product is still on the wall
* I did manage to achieve a more level finish with the trowel than on attempt 1...... it ends there
So I can only assume I'm not soaking the brickwork sufficiently? I came to this conclusion after noticing that when I misted a coarse of bricks and applied plaster straight after, it did seem to bond better.
I'd be grateful if anyone can suggest where I may be going wrong here, the mix was definitely at the correct sand/lime ratio and mixed for minimum 20 mins each time. 2m sq took me 45 mins+ after which I'm in no mind to start another mix! I've a lot more to do and it has to be finished before Autumn when I have a heat pump/central heating being installed.
Thanks in advance