The hole cannot be larger than one-third the depth of the joist, so the maximum hole size for a 2×12 joist (actual size 1-1/2 x 11-1/4 in.) is 3-3/4 in. You can drill the holes anywhere along the length of the joist (first photo). If you have manufactured I-joists, you can drill holes up to 1-1/2 in..
Also asked, what screws to use for floor joists?
Steel Screws The proper steel screw sizes for securing 3/4-inch plywood to the floor joists are #8, #10 and #12 screws. The number refers to the thickness of the screw. Each is available in lengths from 1 1/4 to 3 inches. Typically, the 3-inch variety is used to secure plywood subfloors.
Secondly, how much weight can you hang from a floor joist? If you spread the weight across 3 joists, that puts only 100 lbs per joist (very doable). If you are worried about any potential sagging, you can further spread the weight across 2 bolts per joist, that is only 50 lbs per bolt (very doable).
Subsequently, one may also ask, where can I drill holes in joists?
area in the middle of the 2×10 joist where the hole can go. Although notches aren't allowed in the center third of a joist's length, you can drill holes anywhere along the length of the floor joist in that 5 1⁄4-in. area provided there are no other holes in the joist or notches along its top or bottom.
Can you drill a hole through a support beam?
Shear is greatest near the supports of the beam (the bearing points). Bending is the greatest in the centre of a span. There is an imaginary line through the horizontal centre of a beam, know as the 'neutral axis'. Holes can be drilled through the neutral axis without loss of 'bending' strength.
Related Question Answers
Do you nail or screw subfloor?
When you use a nail gun to attach subfloor sheathing to the floor joists, the nail sometimes misses the joist. Remember, nails can pull up; screws don't. This gives us stronger floors that will not move or squeak.How long should floor screws be?
The 3/4-inch-thick subfloor takes a 2-inch screw. A thicker subfloor takes a 3-inch screw. Use a heavy-duty drill to drive Phillips head wood screws through the subfloor into the floor joists. Drive the screws approximately 8 inches apart.Should I glue subfloor to joists?
Glue. Although using a subfloor adhesive is not required by code, it is a standard practice that can help prevent floor squeaks by reducing the chance for movement at the panel-to-joist connection. A quality subfloor adhesive will also increase the overall stiffness of the floor.Are squeaky floors a structural problem?
In real life, a squeak is no big deal—that is, they don't signal structural damage, like termites, that could cause your floor or joist to collapse. Although any floor can squeak, hardwood floors and staircases are the common culprits. Squeaks happen when a house settles and wood flooring dries and then expands.How thick should a subfloor be?
the subfloors need to be thicker. For joist spacing of more than 16 inches up to 19.2 inches on center, the minimum thickness for both plywood and OSB is 3/4 inch. For joists spaced more than 19.2 inches on center, the minimum thickness for plywood is 7/8 inch and for OSB, 1 inch.Can I use drywall screws for subfloor?
Drywall screws should only be used for drywall, and a temporary coat hanger. You want more strength and need less space for the threads to secure the subfloor. The drywall screws have a lot of thread to hold the drywall itself, but have very little shear strength. In the field between the joists, they are fine.What are flooring screws?
Flooring Screws. (14 products) Flooring screws for a variety of applications such as tongue and groove flooring, including hardwoods, softwoods and fibreboards. Flooring screws can help to prevent squeaky boards and eliminate the need for glues and nails.How can I strengthen my joists?
As incremental parts of a building's structure, joists are not easily replaced. You can, however, strengthen the joists by securing another length of wood to the existing joist, called "sistering," or reduce wobbly floors with block inserts between the joists, called "blocking."How do you attach noggins to joists?
To give this joint even more strength you can fasten a piece of timber such as 75mm * 50mm into the corner and screw through the joist and the ledger with some 100mm long screws. The short pieces of wood that are joining the joists together are called noggins.Can gas pipe run through joists?
Piping run concealed in finished spaces has to be installed through the joists and protected from physical damage. Or be run in black or galvanized steel. Or you could box the pipe run and shield it. Also, a flexible appliance connector has a length limit of 6 feet.How much of a joist can be cut out?
The maximum depth of a notch at the end of a joist (where it rests on a wall or beam) can't exceed one-quarter of the joist depth. Maximum notch depth in the outer third of a joist is one-sixth of the joist depth. Limit the length of notches to one-third of the joist depth. No notching in the middle third of a joist.Can you run ductwork through floor joists?
Here's a joist cavity being used as the main return duct. This is also the location of the air filter. This is a panned floor joist cavity being used as supply duct. Drainpipes should not pass through ductwork.How much weight can I hang from my garage ceiling?
How much weight can I hang from my garage ceiling? If you have another floor above your garage, the ceilingfloor structure can usually support up to 40 lbs/SqFt (including the weight of the floor above it). If you do not have another floor above, the ceiling trusses may only be able to hang a maximum of 10 lbs/SqFt.Can my ceiling support a hanging chair?
Locate a ceiling joist in your desired location that is at least 2 x 6-inches to ensure it can support the weight of the chair and person sitting in it. If your porch ceiling is covered, use a stud finder to locate a joist, which are typically horizontal ceiling supports. This is where the chair will hang from.How do I find the joists in my ceiling?
Use the tape measure to map the rough location of the next joist, roughly 16 or 24 inches away from the first, and tap the ceiling with your knuckles or sweep a stud finder over the area to pinpoint the joist's location. Repeat for any other joists you need to locate.Can you drill into a load bearing beam?
Shear is greatest near the supports of the beam (the bearing points). Bending is the greatest in the centre of a span. There is an imaginary line through the horizontal centre of a beam, know as the 'neutral axis'. Holes can be drilled through the neutral axis without loss of 'bending' strength.Can you drill into a load bearing wall?
Load bearing walls can have holes drilled into them not to exceed 40% of the width of the stud without compromising the integrity of the structure. Non-load bearing walls can have holes drilled into them not to exceed 60% of the width of the stud.Can you drill into structural steel?
In general, it's a good idea to drill through metal using as slow a speed as possible using a drill bit for metal. Hard metals like steel and larger drill bits require even slower speeds. With a small twist bit (1/16 in. to 3/16 in.), you can drill through most metals at 3,000 rpm. 
William Jenkins 
