Advice needed for fireplace surround

[Raymond Fries]

I had an 8/4 poplar board 13” wide x 10’ long and decided to use it for a new surround for our fireplace. This part of the frame finishes out to 6/4. The sides are 2 ¾” wide and the center spacer is 2 ½” wide. I will be cutting an arch in the spacers and recessing a panel in the opening. I am planning on using biscuits to connect the sides to the spacers.

Part of the board had a check on one side but thought I could still use that part of the board for the spacers. Each of the four spacers is made from three pieces with just glue holding them together. I used biscuits to span the check on the back side.

I started thinking about humidity in the shop and in the house. We have one of those Oregon weather stations. It probably measures RH and not SH. The garage was 61 and house was 51 today. I have a dehumidifier for the garage but I have just to ran it for a while because of a flooring project I just completed. Finally done! I was going to turn it on and wait a week before assembling the frames but now I have questions and I am looking for some advice.



Do you think the center pieces are a bad plan? With the change in humidity, the wood will move along the length and with the biscuits, it might not be able to. Just do not want to see it crack anywhere after completion. Should I remake this with dryer wood after the humidity drops closer to what is in the house? Aside from the humidity, do you think these are stable?



For whatever reason, on a few of the joints you could see a “little” daylight along the edges but it did not go deeper that maybe ¼”. I doubt if the gap was wider than a .001. When I glued it, the clamps pulled it together and it dried gap free. Do you think this will ever separate and a crack will appear?


Thoughts please as I have never built one of these before.

Thanks

[Kevin Groenke]

Do you think the center pieces are a bad plan? With the change in humidity, the wood will move along the length and with the biscuits, it might not be able to. Just do not want to see it crack anywhere after completion. Should I remake this with dryer wood after the humidity drops closer to what is in the house? Aside from the humidity, do you think these are stable?



Thanks


Hello Raymond,

Since you asked, I suspect that you already know this but...

Anytime you have wood grain intersecting perpendicular, you need to account for dramatically different rates of expansion and contraction. In the case of your fireplace surround, the wide, glued up center sections are going to be dimensional unstable with seasonal change: the width will change 1/8" or more between summer and winter and it may not remain flat. If you intend to join those pieces in the manner laid out in the photos, you are going to have to employ joinery that will allow for the expansion of the center sections: this probably means that they cannot be glued since the movement of the wood will cause the joint to self-destruct if you glue it.

A more conventional and viable method to construct this panel would be to break up the center sections with frame and panel joinery to minimize the amount of cross grain joinery. You could also probably get by orienting the center section with the grain oriented the long way rather than the short way though that will change the look of the piece considerably.

-kevin

[Mel Fulks]

I'm not crazy about using checked and cracked wood ,but if you can not easily get more material,then I would proceed.The heat from the fire and dryness usually distort these things some over time anyway. Look at some old ones. A good design will still be good even with some age flaws. I think ,from a design standpoint,that the stiles are too wide and the panel area is too narrow. IMO the arch is not going to help this particular design .I would use flat wider panels, narrower stiles, and bold moldings. Would consider perhaps marbleizing the panels to contrast to the frame. Do an arch on something else. Good luck!