I am going to install a Contura I7 in an open fireplace; it will fit perfectly sideways once I've removed the fireproof bricks, but the opening is too high.
Can I use regular coarse concrete to cast the bottom, or do I need to use something that withstands heat?
Attached is a photo from the front. I also need to "fill" or plaster the sides and the lower edge once the opening is reduced. What product should I use for this?
Since you will have a stove in the hole, you can do as you wish. The easiest way might be to remove the fireproof bricks you don't want. Then fix a height-adjusted stone (brick, leca, lightweight concrete block, your leftover fireproof bricks, etc.) at the top to reduce the height of the hole. Plaster everything with regular plaster mortar and paint white, done!
I have now removed the firebrick. As you can see in the picture, only about 9cm is missing.
I didn't understand your answer; does coarse concrete work to press down the firebrick, or is there another product that works better? Please link to a product.
I also thought about making a hole for airflow above the stove and installing a fan in the "compartment" below to get some circulation.
I would have used mortar and fixed a stone of some kind to make the hole smaller, alternatively build up a frame and then put the fireproof stone back again deepest towards the stove.
A grill that F.L suggests is probably a smooth solution that allows you to get good airflow around the stove.
A grill is already purchased, so a hole will be made in the upper part of the stove.
Attaching a picture for explanation.
The stove comes with a cover frame that creates a nice "finish" against the stove, so I would prefer not to have any grill around it.
Since I need about 9cm more, I was thinking mortar + 75mm lecablock. Do you think that will work?
My experience with the same operation as yours is that air circulation out through the hole over the insert works excellently...
If you have a hole underneath, the air will circulate well...
However, it does get quite warm in the ceiling now, so I'm going to install a fan there to push down the warm air...
Now I've made some progress, opened up the hole that will help the air circulate.
Also drilled a 100mm hole under the stove where the fan will blow in air.
I'm planning to upload as many pictures as possible since I missed having them when I started the installation.
