Hi,
Working on preparing the wall for the installation of a new fireplace (with built-in firewall). I got advice from a professional to mount "minerit" (Cembrit/Swisspearl, multi force) as a surface layer behind the stove and then plaster it. Done and done, the boards are now in place with adhesive and screws. After much googling, I've realized that the Multi Force contraption cannot be surface treated in any way according to the manufacturer except for painting with silicate paint. Had I seen this before, I would have bought something else.
There's no compromising on aesthetics, and panel joints must disappear according to us who will live with the stove, so I'm going to give this a try, even though the outcome is likely not to be positive.
The current plan consists of:
1. primer? Unsure about the primer. The Multi Force surface is smooth and absorbent. Any primer must be heat-resistant.
2. A thin layer of mortar with good adhesion, like plaster mortar. I found this which sounded appealing with fiber reinforcement and heat resistance.
3. Reinforcement mesh + corner reinforcement, either metal (19x19mm) or fiberglass (4 or 6 mm). Vertical joints with a minimum of 100mm overlap. Either I'll press it into the adhesive or I'll have to attach it in advance somehow. Unsure if a staple gun will work.
4. Plaster/mud/microcement as the surface finish.
Opinions are welcome!
Working on preparing the wall for the installation of a new fireplace (with built-in firewall). I got advice from a professional to mount "minerit" (Cembrit/Swisspearl, multi force) as a surface layer behind the stove and then plaster it. Done and done, the boards are now in place with adhesive and screws. After much googling, I've realized that the Multi Force contraption cannot be surface treated in any way according to the manufacturer except for painting with silicate paint. Had I seen this before, I would have bought something else.
There's no compromising on aesthetics, and panel joints must disappear according to us who will live with the stove, so I'm going to give this a try, even though the outcome is likely not to be positive.
The current plan consists of:
1. primer? Unsure about the primer. The Multi Force surface is smooth and absorbent. Any primer must be heat-resistant.
2. A thin layer of mortar with good adhesion, like plaster mortar. I found this which sounded appealing with fiber reinforcement and heat resistance.
3. Reinforcement mesh + corner reinforcement, either metal (19x19mm) or fiberglass (4 or 6 mm). Vertical joints with a minimum of 100mm overlap. Either I'll press it into the adhesive or I'll have to attach it in advance somehow. Unsure if a staple gun will work.
4. Plaster/mud/microcement as the surface finish.
Opinions are welcome!
Responding to myself, remains to be seen how it holds up but here is the process I adopted:
1. Sealed any gaps between my panels with Sikasil 670-Fire.
2. Cleaned the surface of the panels with a cloth dampened with Fixor By Nitor Cleaning Wash.
3. Norgips Plaster Compound.
4. In the wet plaster, applied a fiberglass rendering mesh 4x4mm (Biltema), several strips were required, 10cm overlap. Also a Finja fiberglass corner mesh (6x6mm grid) over the outer corner. This was also overlapped 10cm over the other mesh.
5. Will sand down the largest irregularities.
5. Render Mix B hand (80%) mixed with the above Plaster Compound (20%), will then be applied on top of the plaster compound.
6. Painting, guessing silicate paint? A bit unclear yet.
1. Sealed any gaps between my panels with Sikasil 670-Fire.
2. Cleaned the surface of the panels with a cloth dampened with Fixor By Nitor Cleaning Wash.
3. Norgips Plaster Compound.
4. In the wet plaster, applied a fiberglass rendering mesh 4x4mm (Biltema), several strips were required, 10cm overlap. Also a Finja fiberglass corner mesh (6x6mm grid) over the outer corner. This was also overlapped 10cm over the other mesh.
5. Will sand down the largest irregularities.
5. Render Mix B hand (80%) mixed with the above Plaster Compound (20%), will then be applied on top of the plaster compound.
6. Painting, guessing silicate paint? A bit unclear yet.