Chimney flue cover plate – A few months ago came a question regarding whether it is possible to change a fireplace site and if its execution is very complicated. Of course making two holes in the slabs plus another on the deck is not in any way economic and precise hiring a professional. Before making the holes you should make sure that there where you are going to want to do them there is no beam (therefore ask architect plans, etc.).
The lid should be tight to the chimney to be able to work properly and avoid being blown away by the wind. We recommend, if you can, the second option, to remove the pipe from the chimney by the facade. As far as the elbow is concerned, as long as it is 45º, almost any maker will allow it and will be able to ensure its proper operation.
Along with making a hole in the deck is delicate, outside the structure itself, also because it is required to finish the waterproofing of that new hole. This solution will therefore not be the most economical. You will have the proper dimensions of the fireplace so as to purchase a suitable lid. Assess the width and length of the chimney flue cover plate if it is rectangular, and measure the inside and outside diameter of the chimney if it is round.