Excellent job Frankie!! I'm anxious to follow along and take part in this series.
I would like to see a discussion on each of the following topics:
1) wicking moisture from a masonry substrate
2) compression thoughts (which we are already "into")
3)structural intergrity (non-masonry floor)
4) Long Term moisture exposure and resutls
Most of my concerns have to do with the subfloor rather than the actual flooring itself. Compromising of the subfloor has much more dire effects than simply problems with the top layer (hardwood, carpet, vinyl etc).
I have some experience related to this field. I don't install or repair floors but I do work in the design/engineering aspect of construction and have seen more weight related problems and rebuilds than I care to admit. Now I admit I have only seen ONE such problem that was aquarium related but have seen a couple of small hot tub and fireplace related failures. Each one was directly connected to poor design/construction and or inferior materials.
When you have this much time and money invested in a tank this is no time to take any shortcuts. If you're in a hurry you're only going to suffer over and over again.
When you take the thread that Frankie and I started this discussion on
My 120 to 300 upgrade...it begins!
you'll see that I somewhat duplicated something that he suggested. I mentioned treated wood in contact with the masonry slab in which a 300g tank was being installed due to the fact that all concrete will not only wick moisture from the ground (it's a building code that ANY wood in direct contact with the ground or masony units MUST be treated when building a new home so why wouldn't you use treated when building your new stand) but it will also give off the moisture from within itself for many years to come. Concrete is not FULLY cured for upwards of 50 years even though after about 5-10 it's 95+% cured. My thought is that a person should NOT use treated plywood in such an instance because the variations within the plywood could lead to uneven compression along the sub-frame of the stand and in a rare case could put stress into the tank where stress is not intended or designed for. Unless you order VERY high grade treated plywood it is rated C-D which is less than appearance grade (A-A, A-B or Select for cabinets). It will have randomly scattered "football plugs" (this is where knot holes and imperfections were removed by a machine and the resulting holes are plugged with indeed football shaped plugs). These plugs are usually a much denser (harder) material to compensate for lack of integrity of the material around it due to interruption in grain. What this boils down to is that the PLUG is harder and doesn't compress at the same rate as the rest of the plywood. Given that most stands are designed to carry the FULL weight of the tank and everything else along the perimeter you can see that the weight concentration is very HIGH along this area. If you happen to have a plug right in the middle of a span and no others, you have a high potential for uneven compression. The middle could stay high with the ends dipping ever so slightly. You have now introduced a high stress point right in the middle of your tank along that axis. See where this is going?
Now this only really affects plywood that's on a hardened substrate that does NOT allow for sagging! If this same set up is placed on a truss/floor joist system the entire floor is actually designed to sag and give under normal weight loads and carry these loads to either a perimeter or intermediate point and then down into the foundation. In most instances you can't see or feel this sag (at least we HOPE you can't) but it's there and designed in. This is defined as an L/# (called L over..). This is actually calculated into the floor system and if your contractor/designer knows your going to be adding something massive in a certain area or room it's as simple as increased the l/# value to compensate for it.
Hope this doesn't cause more confusion than it helps!
Allen
