Structural Engineering Other Technical Topics

Utilize this Pressure-Treated Plywood Rated Sheathing for building barns, playhouses and sheds. In most cases it’s best to design your furniture with reinforcing elements to add strength and stability; the best plywood won’t make up for bad structural design, but good design can make pretty crappy materials work out okay. Pressure treated wood is wood that has undergone a process to make it more durable so that it is not susceptible to water, rot, termites, or fungus.

Plywood will often splinter on the edges when cut, so it’s harder to get a smooth cut with plywood than it is with MDF. I can find information redily enough on the strength of joints but can’t seem to find a reference for plywood on the vertical like I can for hard and soft woods. Plywood comes not only in different thicknesses, but also in different grades, so you can choose the right one for your project. The 3/4 plywood I removed would have been ~165 lbs.. Replacing with 1/2 plywood would end up ~110 lbs before epoxy/glass. Standard panels are 4 feet by 8 feet, but the Homasote Co. also offers 4-by-10, 4-by-12 and 8-by-12 sheets 1/2 and 5/8 inch thick.

The flooring can be laid parallel to floor joists, but you may need to add a 1/2-inch layer of plywood diagonally or perpendicularly to the joists, or install a brace between the joists. C-grade (plugged) permits synthetic repairs, splits up to 1/8-inch wide and knotholes up to 1/2 inch diameter. Look at all the things that get put in cardboard boxes and bet stacked on a pallet then stacked two and 3 high and the bottom carton doesn’t crush. This begins to explain the product’s odd sheet size of 5’x5′ (more about this at bottom). The most expensive option in that list ends up running me $72 for the equivalent of a 4X8 sheet of plywood.

I know the weight would vary by how long the posts have been outside, asorbing air moisture, etc etc, but I am looking for an approximation, based on posts that are 3 -4 months aged. This will be especially helpful on the large curved sides of the hull where bending a 3/4 inch thick sheet of plywood would be difficult and add considerable stress to the hull. I think for the quantity I need the 3 gallon kits raka or duckworks sells would be economical while still providing headroom for waste.

Similarly considered something like poplar or hardwoods that can be had in 3/4 planks at a reasonable cost (did not do all weight calculations but suspect poplar in 3/4 similar or lighter than ceder 1.25). Monsterliner is an option that works, but only if the the whole structure is coated, meaning if using plywood (for example) all sides and edges need to be painted with this goo.

Obviously these types of plywood don’t need to look pretty since they’ll be covered up. Add 2×4’s around the top and bottom on the inside, make a base from 2×4’s that are lap jointed at the corners, screw that onto the cabinet base, add your casters, attach your top of 3/4 or double 1/2 stuff (plywood, mdf, particle board) and you have a very strong box. Its a little hard to see in the left picture, but there is a space between the forward and aft insulation panels just wide enough for a half inch PEX line.

I made one with 3/4 plywood sides, hardwood frame, solid maple top holding a 50 gallon tank. Our buddy Todd over at Home Construction Improvement swears by Advantech Sheathing , a next-generation surface that resists moisture much better than either plywood or OSB. A 3/4 inch thick home made plywood cabinet is probably 10 times stronger then a stock cabinet that’s available at the aquarium store – it can be nailed and glued together. With close inspection of Baltic birch, you should notice that the face and back veneers are remarkably thicker than the veneers you’ll see on traditional cabinet-grade plywood.

That is similar to the style of case construction I was thinking and it will hold less weight than yours. The floor is going to be 42′ by 22′ it will consist of either 1/2 inch OSB or ply wood placed on top of high density foam blocks. Will tell you how much load plywood can handle when the sheet is put in compression on edge. Depending on the adhesive used, the plywood is graded for interior or exterior use.

While most plywood does contain urea-formaldehyde and other VOCs, it is now possible to purchase plywood without formaldehyde. The 2 x 2, front, back and sides, gives good suport, and will hold 3 feet of records Otherwise, you need some sort of bracing on shelves or they will sag. Chart represents most common plywood sheet sizes in inches (imperial system) and millimeters (metric dimensions). There is a strategy that reduces sag, particularly if you are using a 3/4 inch shelf with additional lengthwise structural supports, such as 2 X 2 supports or other forms of lumber under the shelf.

Over the last 15 years, CLC has developed a specialty in shipping plywood all over the United States and become one of most widely used marine plywood suppliers in the the lower 48 states. The strongest of all plywood is used for concrete forms, stair risers and industrial flooring. Below-grade areas of the home where the soil is 3 inches above the floor, such as walk-out basements, also have slabs. My general contractor suggested I use this design but add the second piece of plywood on top. The Fire-Retardant Plywood conforms to AWPA C27 type A. – Sanded and good one side.

Marine grade plywood is often use for boats because is is constructed from more plies than regular ply wood and more care is take to make sure there are not voids in the ply that would cause a weak spot. The cheaper option is more like $40 (ends up being they sell ceder fencing material in a 3/4 X 5.5 inch X 6 foot). Individual layers can be counted by looking at the edge of any piece of plywood.

Nails or screws to fasten fence of pressure treated (ACQ) southern yellow pine lumber. It’s more difficult to cut detailed designs into plywood (scrolled, scalloped, etc.) because the edges will splinter, and then you’re left with edges that show layers and might possibly have voids in some places. The outer layer of plywood can be damaged and allowing water to seep into it’s layers and weaken it, but the epoxy glue between that layer and the next will prevent the water from reaching the second layer. Steve – If I make the case in plywood I will use a combination of dado and rabbet joints reenforced with cleats.

Normal exterior grade 3/4 inch 4×8 foot sheet plywood from the local lumber yard is about $20 a sheet, but it will likely have voids inside and the wood used to make the layers or plies will have knots so it is not as strong as marine plywood available local contractor lumber suppliers like M & M for $75 a sheet. Particleboard is frequently discovered as a subfloor layer over plywood when carpeting or vinyl are ripped out.