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How do I reinforce the floor for front load washer

48508 Views 15 Replies 6 Participants Last post by  EasternCanadian
How do I reinforce the floor to avoid additional structural damage caused by front load washer?

I believe the vibration from the new front load washer has caused problems in my home addition/remodel. The tiles in the laundry room are cracking, the taped joint (wall & ceiling joint) in the kitchen (shared wall with new laundry room) is coming down, there is a crack on the wall above the door and the door no longer closes.

The vibration can be felt in many places in the house, not even close to the laundry room.

In addition to reducing the vibration source, I want/need to reinforce the floor since some vibration from both the washer & dryer will still exist. How do I do this?
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What's there for floor joist now?
What's the span?
floor issue

What is the condition of the floor joists? If they are solid, it may be the subfloor either being damaged or not fastened properly, allowing for some viration. Normally the dryer or washer do not vibrate to the level where they cause damage. Another question, ... are the units level and all four legs touching the floor as they should? Find the cause before doing the repair or your just doing a bandaide job.

The space between the floor joists is 17". This is new construction - an addition to the house. We expanded the house where we previously had a carport, now we have a garage, laundry room & bedroom.

From the crawl space, I can see the floor joists and plywood. Also, the laundry room had backer board and is tiled. All work was on permits. We have noticed other quality issues (lack of quality workmanship) since the end of the job.

We originally thought the drywall tape seam coming down was just an isolated, odd thing (bad joint compound) but then the door would no longer shut. Vibration from the washer is most severe along the line of the floor joists from the laundry room. The microwave is in a microwave cabinet attached to the kitchen wall (shared wall with laundry room) and the microwave vibrates and makes noise when the washer hits the spin cycle, same with the stove.

I can take some pictures if that helps.
Yes, the washer & dryer are level. We also bought some of those square anti-vibration blocks for under the washer feet but it didn't help much.

That's why I'm asking for help - don't want to just bandaid the problem, want to fix the cause, then the cosmetic issues.

If we have to rip up the floor, we will but since it's new (not rotten from being old or water damage or anything like that) it shouldn't be materials.

Do wooden floors under laundry rooms need special reinforcement? Or is this a relatively new issue with front-load washers that have higher spin cycles. I never had a front loader before, my old washer was pretty old, so we didn't initially realize that could be causing the problems.

Traditionally the floor doesn't require any extra support. The floor joists should be level and be supported by the walls at both ends and in the center if it's a long span. Sometimes the center support settles and the joists drop a fraction. If this is the case you can shim the floor joists or if you have a telescopic type post, it can be adjusted to bring the joists back to level. The joists are usually covered with a 3/4 inch sub-floor. If there is addional thickness, it is usually there for suppour and stiffness for items like slate flooring or ceramic. Check the levels first and do a logical backtracking from there.
Just a case of building the the codes (the worst you can do and be legal, but not necessarily right). Codes are not the way it should really be done.

When it comes to vibration and dynamic loads codes may not be adequate. You can try to add as much solid blocking between the joists to increase the lateral stiffness and distribute the dynamic loads horizontally. Dynamics are very unusually and depend on frequencies that can amplify the loads and responses. Codes are archaic and cannot be a cure-all for newer special situations.

Thanks so much for all the info. I did check the floor in the laundry room and it is not level in the direction that the joists run but is level the other direction. The new wall that is shared by the kitchen on the east and the laundry room & bedroom on the west is basically where the spot where the new construction meets the old construction.

It is possible to get into the crawl space and add blocking between the joists. Should this be done just under the laundry room or would you recommend the whole span (about 16')?

Once I get the vibration issue fixed I will need advice on fixing the tape joint that is falling down. Also, I have tile issues.

We did get some of our money back from the contractor for work not finished or bad workmanship but basically it's all on us now. I currently unemployed so we aren't in a position to hire someone else - I will try to fix as much as I can.

I appreciate the help very much :)
Still need to know the spec's on the floor joist.
Span, width, spacing.
If he used to narrow a joist then there's most of your problum.
You said it's a 16' span but is that a clear span with no support in the middle?
The plans say the joists are pre-fab. Joists are 12" with a 2 3/4" board top & bottom. Nothing between joists.

I tried to attach a photo.


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More photos: the ceiling/wall tape joint, crack over door and ceiling joint, joists


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Normally, people think of loads as being up and down (gravity).

when you throw a piece of equipment that rotates at defined rotational rate there are many other forces induced.

The photos show a very light (not good) and spindly structural system to carry vertical loads, but worthless when there are lateral or uplifts that can multiply and cause deflections that can create cracks. Lateral bracing/reinforcement or mass/weight are ways of minimizing the effects on the surrounding structure.

Another method is isolating the equipment from the structure with isolation pads.

So what needs to be done... reinforce the floor, the wall, or both?

Reinforce with what and where?

WE MIGHT BE ABLE TO HELP. E-mail me at [email protected] Our floor bridging system may be able to help this problem.

Diagonal 2x4 braces going from the bottom of one joist to the top of the next would work best with the floor joist you have. I do not have the exact angle, but with your 19.2" spacing and 12" depth it is likely approx 35 degree miter. Run the braces horizontal (with square cuts) where the dryer vent passes through (above and below the vent). I would block the entire floor, probably two runs (dividing the floor into thirds as opposed to one run of blocking down the center). i always glue my blocking with a construction adhesive (like PL premium by LePage). This is a lot of work, but once you find the angle you will have your template for every other piece of blocking.

FYI Every front load washing machine I have seen is designed to be installed on a concrete surface, either pad or over-pour. Also, i did not see a floor drain, highly recommended to have a floor drain in a laundry room.
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