Hump Date

Wendy’s Blog

When wood stresses and does weird, wonky things! 

Being natural material, wood reads like a book, and reacts to things its exposed to.

Ten years in it never ceases to amaze me what I learn from working with wood. Even a colleague, with 20+ years on us says the same thing! To be honest, working with wood keeps you on your toes for sure. And this past week was no different!

A client calls after being referred to us from a premiere handyman service, Mr. Handyman of Moorestown.. Owned by Ray Weise, and capably represented by Courtney on the phones, they surf through their customer calls and refer out what is beyond their covered services, and this particular call was one of them.


Our prospective client reveals her wood floor has a trip & fall hazard that must be fixed before they list the property to rent.

What in the heck is that? My first thought- "bizarro!" I have never seen anything like this. A weird hump in the floor in a random location.

Overall the floor looks wavy, across 2/3rd's of it. Dialing it down, there is cupping along the board edges. Cupping is a wood condition where the edges peak up, and look dissimilar.

Weird hardwood floor problems in Maple Shade

This hump did not relate to anything, so with all the waviness to the floor, the wood was screaming something- but what?

Well this is a first! I had never seen anything like it. But when I asked her about if she saw it before this happened she explained. She said that they moved in, and about 4 months afterward this weird bump appeared, some 4 yours ago. As part of my diagnostic I asked if they had any signifcant ‘water event’, to which she said no. I did point out that the waviness in the floors did indicate that there is a moisture problem. I further explained that the bump could be moisture related as well. 

I asked to see the basement, but she said there was only a crawlspace, and with little access. It was in a closet through a hatch in the floor. 

Taking me to the closet she was unable to open the hatch. 

So after another question regarding any ventilation in the crawl space, she remarked there is one at the far end of the first floor, no where near this hump in the floor. She then informed me where it was had earlier been a porch addition.


cupping on hardwood over wet crawlspace
See the edges of the red oak boards, they are "cupped" from exposure to moisture from the subfloor

Looking across the floor there was definately a moisture issue.

Doing dectective work on the floor where the weird wood thing is I noticed that over 2/3 rd’s of the boards had cupping along the sides. Most of the cupping was located in the added room, which formerly had been the porch.

 There is more along the south wall near the former front door, in and around the windows and off where the fire place is located. 

Conversely, toward the kitchen near the east side of the house, and the other entrance there is no cupping. Also , walking upstairs, it appears as though the plumbing, and chance of pipes running under where the hump was, is located far away from the problem area, which is right at the bottom of the staircase. 

Also, another piece of the puzzle, but not key problems, I noticed a steam mop in the kitchen, and 2 products with shine ingredients. A steam mop is a big no-no for cleaning floors, as it will “blow the finish” and cause issues eventually with hardwood floors. And two, shine restoring products, if overused, will create a mess on the surface of the floor that may need professional stripping to remove. Not to mention, it also will eliminate the option of lightly abrating (sanding) the floor and top coating with finish. Making note of these clues, we would get better clarification when we could speak with the owners, and get a look underneath.

So we planned to get into the crawl space the following day, and we sought some wood consulting.

Knowing which way the floor joists ran, and looking for things like settling and leaky pipes, we got some pointers from our own ‘wizard of wood’, Bob Goldstein. He affirmed the crawlspace would likely provide the telling clues as to what’s going on down under that is stressing the wood floor above.

Chris and I returned the following day, with a step stool in hand. He got the hatch open, and went down under.

First, the crawl space is dry in terms of no ‘easy’ water (visual water seen puddled on the floor, or puddles that dried on the floor). In fact, the hygrometer readlings were between 10-15% (damp for wood in November, but not ridiculous). Secondly the floor joists run the opposite direction of the hump in the floor. And thirdly, there were no pipes in that area at all. 

So the next thing was to locate where the hump is. So Chris had me marching on top of the floor, on the raised boards while he listened and located the stressed area from below. Didn’t take long. Apparently the original house has tongue and groove subfloor, and the enclosed porch has OSB, a newer cheaper subfloor surface more currently utilized.


Bingo, the wood weirdness is identified!

hardwood floor damage from poor installation
To the left the nail is missing, to the right the nails missed the joist causing the hardwood floor damage
Water damage proof of subfloor failure causing hardwood floor stess
Here is the evidence of water that forced the subfloor to swell and push up the hardwood boards above it

Turns out the tongue and groove subfloor, a sturdier heavier floor material had swelled up from moisture absorption into the wood, and was no competition for the nails that were used to nail it to the floor joists. And further, there was sloppy contracting also at fault. In the area of the swelling some of the nails hammered in from above during installation didn’t even make it to the joist. The nails missed the joists, and there was a large area that was missing nails all together. 

Installing subfloor with nails is "old school", with the advent of screw guns, using screws secures wood far better than nails.

So with a combination of poor workmanship and vunerable fastening, the heavy dense tongue and groove was no match for the nail pattern once it became damp with moisture. 

Wood swells and contracts with seasonal moisture. During dry times you see bigger gaps between the boards, and during the summer and humid months you see the gaps are less noticeable. 

That is just the way of wood being a natural material. Like plants, they absorb water.

But with installed wood flooring, and particularly with harder, wider and denser wood, it has a ‘mind of its own’, and more likely to move, contort, or cup with moisture.


More detective work ensues, as Chris looks for crawlspace ventilation, which is little, almost none.

In the general area of the distressed wood, both the humped’ area and the extensive cupping, there was but one vent in that area of the crawlspace.

Now consider that in summer months the humidity and moisture probably well exceeds 15 %, probably north of 20-25% moisture. With it no where to go the unnailed area of the floor, and all the boards are reacting to the moisture by moving, swelling, and distorting. 

Of the possibilities, this cause of this wood distortion was the best possible one to hope for as it did not involve structural intervention or plumbing repairs!

If the cause were structural settling is involved, relief efforts may involve repairs to floor joists, sistering the joints, jacking things up, and replacing the sub floor. And along with that structural engineering may be required. If the cause were a plumbing related issue a plumber may be required to mitigate the cause. If it were static pressure (where water migrates into a basement or subflooring), waterproofing efforts with french drains may be necessary. 

Clearly all the above reasons mentioned above could have caused this obvious distress to our clients’ floor, however non were the case. The existing subfloor could be resecured, and not replaced. And with some simple ventilation tasks the problem could easily be resolved without involving major structural or plumbing expenses.

With answers provided, we give the scenarios for the repairs. of the floor, and cooresponding recommendations and estimates for all.

If you have waves (aka cupping) where the edges look wonky and not flat, or have raised areas like this one, or an uneven appearance that is not flat we can help. Free estimates Call Us,  or Contact Us on line and we will reach out to you.