HELP - insulation board flaking and falling apartI

[jar648]

My contractor installed a Chicago 500 kit last summer. I noticed a bunch of material falling beneath the oven. Turns out he installed the insulation board BELOW the metal plate. I have an open log box below the pizza oven and the boards are exposed. The span across concrete support pieces. But the boards are SOAKED maybe from rainwater coming down the chimney

[Gulf]

Water can certainly come down a flue if there is not a suitable cap installed. I don't recognize the oven model name. Is it a Chicago (Brick) 500?. If it is not a Forno Bravo oven I may move your question to a different subforum. But, we may still be able to help troubleshoot the problem. However, you will need to post some good pics of the flue opening, the oven and how it is placed on the stand.

[jar648]

[jar648]

Photos 1....

[jar648]

Sorry trying to get used to this mobile app

either water is coming down the chimney surround (not the flue). Plus general moisture from below.

but I could easily rip off chunk after chunk of the ceramic board from below. I would imagine this would deteriorate over time, and the oven would collapse 2 inches and be supported by the concrete below the insulation board. But it would compromise the whole custom blue stone surround. I don’t know what to do at this point.

thinking about maybe using fire insulation spray around the top of the chimney to prevent rain from coming in around the side of the flue and draining down. And then spray insulation from the lob box below to keep humidity away. Otherwise ripping this out and rebuilding structure would be a massive undertaking by contractor since it’s built into a 30 linear ft outdoor fireplace, sitting wall etc.

[Gulf]

Kind of diffucult to tell from the small pics, but it looks like the oven is surrounded by unfaced block. They can soak up plenty of water. The flat top can also be channelling mass amounts of water around the dome down to the underlying insulation.

[Gulf]

Sorry. I wasn't looking at a finished pic. But, it looks like another structure is shedding water directly on to the oven. You may have water entering the door.

[jar648]

Thanks. Just to explain I posted pics of the finished product, as well as the door removed and front ledge removed. There is what looks to be cement board powder all around the inner crevices of the front ledge. While water may be coming in from the front I think it’s also coming in from the area between the stone chimney surround and the metal flue. Allowing water to flow over the oven and soak the base. Because the whole cement board base is soaked, not just the front by the ledge, water must be coming from above not just the front.

my initial thought was to use high temperature spray foam to fill in the cavity towards the top of the chimney cavity to prevent water from coming in and/or pooling in the chimney cavity. But the foam will be touching the flue and I’m not sure if it’s a fire hazard. The flue is double walled but gets plenty hot since it’s only 24” in length. Also, another thought is to raise the front ledge. It is half an inch lower that the oven floor. Water could be coming in there, and it should be that way anyway since it’s not flush with the floor of the oven which making things difficult to pull out pizza.

but the above could be all for nothing since the instructions clearly say the metal plate should be below the insulation boards. They installed backwards. The boards are exposed to the open log box below. So humidity and moisture will be attacking the boards and would eventually deteriorate over time.

[jar648]

Hey gulf - I think you’re right. I am trying some things to keep water out from the front.

however in regards to the sections of cement board exposed from below, do you recommend I spray fire insulation over it to keep humidity out?

[Gulf]

No. Just keep it from getting wet any further. Anything that you do from unerneath may just seal the moisture in. You want it to have a way to get out.