Help with register plate

[Sidcup1]

Hi there,
About to fix the stainless steel register plate to the bricks at the top of my entry arch. I intended to place high heat silicone around the area to seal beneath the plate, and screw it down with tapcon screws and non galvanised washers so it can move. The silicone is only rated to 300 deg C ....is the reg plate gonna get hotter than this ? There are other cement ones available rated to higher temps but are not suitable for outside.
I intend to render (stucco) around ss chimney and bricks and seal around where render meets chimney to seal it from weather and give an expansion space. The temp limit of 300 C wont matter here as it is a twin walled pipe.

[UtahBeehiver]

I not sure what a register plate is but I am assuming it is where your SS Chimney attaches to the brick. There is a high probability that the vent gases will exceed 300 C or abt 570 F. There was recent discussion on this very topic of what type of sealing compound to use. There are refractory sealants that are rated 1800-2000 F such as Kawool modeable caulk, UniExtreme, Dap High temp caulk. I suggest you check with a local fireplace or refractory supplier in the UK.

[Sidcup1]

Thanks for the swift reply !

[Saluki]

I mounted mine per the manufacturers recommendation. Used steel anchors and bedded the anchor plate into the high heat mortar. You can then dial it in and get it perfectly level and assure you have no leaks.

[Sidcup1]

Yep - i think thats the answer. Thanks guys !

[david s]

If you use anchors make sure they're stainless steel. Anything else in that position will rust quickly from the heat.