Basement Staircase & Weight of WW Machinery??

[George Farra]

Hi Everyone

I'm going to take the plunge and upgrade some of my shop equipment. By the summer, I'm hoping to add either a hybrid or cabinet TS, an 8" jointer, and a 14" bandsaw.

The heaviest thing I've moved down there was my Delta 6" Jointer...approx 200lbs. I weigh in at 180.

Acces to the basement is via the house. I was looking at the staircase last night and was not constructed in a manner I an familiar with.

There were grooves routed into the stringers. The threads and risers were wedged in place in those grooves and glued in place with construction adhesive. The threads are solid wood...look like pine to me and the risers are MDF.

I'm growing weary that these stairs can handle me (180lbs) and some ww machine on an appliance dolly....even if i break the machine down

Anyone know how much weight a staircase of this construction can handle? Should I fortify it with a center stringer bridged to the studs the side stringers are attached to?

Thanks

George

[George Bregar]

Aren't there stringers also below the treads? I can't believe the entire width of a 36" or more code width staircase is only supported at the ends in the manner that you say.

[Rod Sheridan]

George, I added two vertical supports from the middle of the stringer to the basement floor (2 X 4 C clamped to the stringer) prior to moving my Hammer A3-31 downstairs.

I have the identical stair construction to you.

The Hammer was heavier than what you're considering moving.

Regards, Rod.

[George Bregar]

Are you sure you are not confusing the mop board for a stringer? It's not unusual for the treads and risers to fit into grooves there...but the actual treads should sit on top of the stringers...

[Rod Sheridan]

Are you sure you are not confusing the mop board for a stringer? It's not unusual for the treads and risers to fit into grooves there...but the actual treads should sit on top of the stringers...

Hi George, the stairs in my basement have a 2 X 12? on each side, that has dadoes that the steps fit into. That is what I'm calling the stringer, perhaps that's not the correct term?

The steps fit in the dado, and there is a wedge that fits underneath the step, and there is glue used in the dado.

Hope that makes sense.............Rod.

[George Bregar]

Hi George, the stairs in my basement have a 2 X 12? on each side, that has dadoes that the steps fit into. That is what I'm calling the stringer, perhaps that's not the correct term?

The steps fit in the dado, and there is a wedge that fits underneath the step, and there is glue used in the dado.

Hope that makes sense.............Rod.

Again, that may be the case, but there are stringers under the treads also, no? Just can't see a 36" (or wider) staircase with the treads only supported at the ends in grooves. I'm just wondering if the OP has an enclosed staircase, and he is confusing the mop board, which is just a trim piece, as a stringer. And surely there is a center stringer even if his description is correct...at least I would hope so. I would have no issue with the treads buried in a dado in the outer stringers...as long as there was also a center stringer(s).

[Aaron Wingert]

Putting the treads into a mortised skirtboard isn't all that common but I have seen it done. More on older homes than modern ones. If there's no center stringer I too would have doubts about the treads' ability to span 3' with that much weight on them.

Not sure what the level of finish is, but if it is just framing and no finish it wouldn't be tough to just re-frame the stairs and make them nice and strong.

I have a broken stringer on my basement stairs and am re-framing them with three pieces of timberstrand rim joist to make them rock solid. The stuff isn't terribly expensive and makes great stairs. In your case you could probably re-use the existing treads.

[George Farra]

Perhaps I've also mixed up my terminology, but my staircase has 2 boards (2x10 maybe) at each end of the staircase. The treads and risers are dado'd into those, wedged and glued.

There is NOTHING in the center of these stairs....which is raising my concern of moving heavy loads down into the basement.

I think I am going to add a 2x10 stringer to the center of the staircase for the threads to rest on. That center stringer would need to be tied into something wouldn't it???

Thanks guys for all your input....very helpful

George

[George Bregar]

Perhaps I've also mixed up my terminology, but my staircase has 2 boards (2x10 maybe) at each end of the staircase. The treads and risers are dado'd into those, wedged and glued.

There is NOTHING in the center of these stairs....which is raising my concern of moving heavy loads down into the basement.

I think I am going to add a 2x10 stringer to the center of the staircase for the threads to rest on. That center stringer would need to be tied into something wouldn't it???

Thanks guys for all your input....very helpful

George

2x12 and actually would do two, positioning them 1/3 of the way off the outer stringer. They attach to the floor joist. Lots of DIY guides on the net. Need to very accurate to snug them up to the treads as it sounds like they can not be removed.

[Wes Billups]

George, I believe I have the same style of basement staircase as you leading to my basement. I took a 600# Sawstop, 700# shaper, and many other tools down it with my dad. We both are over 200# so I think you'll be safe. With that said I just reinforced the side stringers with a 16' 2x8 glued and screwed. I also built a wall half way up under the stairs. The bounce they used to have is completely gone. Of course I'm done hauling things into my shop but the changes should help if we ever move.

I hauled everything into the basement before really looking at my stairs. The two stringers were actually 1-1/4" and 7-1/2" wide. Not much support when you figure we were loading more than 1000# onto them. I'd recommend a short wall in the middle over sistering as my biggest fear was them pulling away from the first floor framing. I could only see a five nails holding the staircase to the joist. Plus the sistered stringer wouldn't prevent a step from falling out should the staircase spread open. The wall underneath will allow you to tie the two stringers together so they can't spread apart.

This kind of staircase is common in spec built homes as all the components are pre-cut and go together on site with very little knowledge of stair building.

Wish I had pictures but everythings covered in drywall now so taking them at this point wouldn't help.

Wes

[Kent A Bathurst]

George, I added two vertical supports from the middle of the stringer to the basement floor (2 X 4 C clamped to the stringer) prior to moving my Hammer A3-31 downstairs.

I have the identical stair construction to you.

The Hammer was heavier than what you're considering moving.

Regards, Rod.

Ditto - except I lagged a sleeper to the floor, lagged the verticals to the stringers, and lagged them together via a cleat. Told the buyer of the house they were not needed for normal use - just machinery - and I'd pull htem if he wanted, he said "nope - may come in handy".

[Mike Ruggeri]

Similar to what others have said - I had the same set up in my old house and I moved everything up and down them from a 15 inch planer to a 300lb workbench to a unisaw. In hindsight, I think adding some support in the middle as others suggest is probably a good idea but I had no issues with mine as is.

Good luck.

Mike

[George Farra]

Thanks guys. I feel better knowing that the stairs would most likely hold up under load. I will most likely bridge a temp support just to be safe. A lot of good ideas here....as usual!

George

[Michael Gibbons]

Three stringers held 500 lb Unisaw with two guys around 480 lbs. No other support. Guy with electric dolly delivering 500 lb safe no problem. If your unsure, support middle of staircase with 4x4.

[Doug Carpenter]

I have some friends that just had two 800lb gun safes delivered to their basement. The home is new and the staircase is typical of new construction these days. The saircase is built off site at a lumberyard.

It consists of a 1 by 12 stringer on each side of the 36" treads. There are triangle blocks glued and stapled to the stringer that acts as support for the treads. Often times there is an additional 1 by 4 added on the outside as a spacer for dryall. all in all they are pretty strong as system.

Honestly I was shocked that they didn't break right through the steps. The moving company had a hydraulic dolly that walked the safes down the steps.

The problem isn't so much the constuction of the staircase itself, although I doubt they were desinged with machinery in mind. It is the installation. Not to insult framing carpenters but installing prefab steps is often done very quickly. You can fire a couple of framing nails in it at the top and bottom and it will give the illution of being "correctly installed".

I have done basement finishes in new houses that had staircases held in with two nails!

I would carefully inspect the staircase and besure that it is attached to the surrounding studwalls. Often you can add a 2 by 4 brace all along the bottom of the stringer. a center stringer is nice too but if the treads and risers glues and nailed together they are a pretty decent system. I worry more about the whole staircase sliding and falling than I would it breaking.

As frame carpentry goes the two biggest challenges have always been the roof structure and the stiarcase. Both of wich have changed dramatically over the years. It is not uncommon that the crew may consist of only one carpenter that actually knows how to build them. Unfortunately he can't watch everything that goes on.

It doesn't sound like you are moving anything that heavy but I feel a good inspection and some extra bracing can't hurt.