we have low decks, and a firefighter friend suggested we close them in. He said that leaves and other debris blow in, then if a spark flies under, it is like tinder, and it can take hold before anyone even recognizes there is a fire happening.
I had wondered about critters too, but the fire explanation convinced me we need to close them in somehow

Well, I've had a family of opossums living under my low-level deck on and off for the past year but I understand they eat slugs so that's a plus. I really don't want to know what else lurks under there. Love the deck, though.

Hi Krendar, (Helen this pertains to you as well)

Gonna try and answer your question and add a few comments and observations.

"Animals"...If you go to our website's video gallery there is a video on "How to Properly Ventilate Your Deck" https://www.soluslumber.com/gallery-how-to-videos/ and if you go to about 2:15 seconds into the video you'll see some images of horizontal boards on the side of a deck. Installing some skirting with this kind of spacing, will still allow for some important airflow, but keep larger animals like opossums from setting up residence.

"Bugs".... are much tougher issue and you could back the skirting and the underside of the decking with screen, but is no guarantee.

"Mold".... could be an issue with such a low-level deck, but in this same video you'll see some of the potential pitfalls and the things you can do to minimize them when building a deck low to the ground. It's all about airflow and getting water away from underneath the deck. Depending on where you are in Southern California it should be a fairly arid climate and would think mold would be of lesser concern.

"Fire".... Tropical hardwoods like Ipe and Massaranduba have class A fire ratings which is the same as concrete. All materials will eventually catch fire, but using one of these woods will go a long way to mitigating this issue. https://www.soluslumber.com/ipe-decking/

What kind of material are you planning to use for the decking? We ship to Southern California regularly so don't hesitate to contact us with any questions you may have. As always, please share some before and after photos and let us know how it turns out!