Repairing a split/crack in one of the boards

Q: We just recently bought a new house that has hardwoods throughout. In one of our rooms we noticed a split/crack in one of the boards. Can we replace that piece or repair it in some way? It seems like it could get worse, like someone could catch their socks on it. Any suggestions?

A: Of course, a piece can be dropped in after cutting the old piece out. You will need a matching board, a circular saw, hammer, chisel and some adhesive.

Similar Q: I recently installed hardwood flooring in my living room. One of the boards has a crack in it. It was not there when I installed it. What would cause this? Is there a way to repair it?

A: It was there when you installed it. You just didn’t see it. Now, with shifting of moisture levels it has opened up a bit. Replace the board.

Best product to fill gaps

Q: What is the best product to fill gaps in a hardwood floor? What is best wood filler for hardwood floors? Or putty? I am refinishing.

A: There are a lot of different fillers on the market. I haven’t used them all. Woodwise is OK, but like most of them will crack out if there is movement between boards. The toughest one I’ve ever used is Timbermate but it is quite expensive and difficult to work with. For small, occasional gaps and nail holes I like a tube filler called Color-Rite. It comes in hundreds of tones and is easy to work with and being more of a caulking won’t pop out. There are also stain-able adhesives on the market that have a place.

Related Q: I have old, wide plank chestnut flooring in my kitchen/dining area. The boards are approx. 12′ wide and 1 1/4′ thick. The house was built in 1803. I am looking into what I need to do to prep and refinish (seal) the boards. They have not been addressed in approx. 10 yrs. They are not smooth and there are spaces between ranging from 3/8 to 1/2′. Is there a caulk of some sort that I can fill the gaps with?

A: Wow. I’d love to see that floor! You might take a look at Timbermate:

Related Q: Our old wooden floor has some very small openings (i.e. small pieces missing). What do you recommend we use to fill these small openings?

A: Any colour matched wood filler such as Color-Rite would do the trick (comes in a tube) or any wood filler which can accept stain if you need to match a particular colour. Any wood flooring retailer will carry such products.

What causes cracking in wood boards

Q: What would cause cracking in wood floors, board ends and the centre of the boards 6 months after installation?

A: What species of wood is it? Some very hard exotics seem prone to splitting. Likewise, sometimes a piece of oak can have a crack in it but not be noticed during installation; it can appear later as the floor shifts with humidity change.

A couple cracks and scratches on newly installed floor

Q: I have recently installed hardwood flooring. I have noticed that, on some strips of wood there are scratches and in 2 strips of hardwood there is a crack about 3 inches long. Please advice as to how I could fix this, how to repair cracked floor boards. The hardwood used in this case is cherry kempas.

A: You will have to replace the cracked board, and probably the scratched ones also. You could try hand sanding the scratched boards and applying a water borne coating to the entire strip in the appropriate sheen but I don’t think you will get a match.

Filler that won’t crack?

Q: I was wondering if you could help me with a flooring wood filler cracking / polyurethane issue. My floor was professionally refinished 1 year ago and was to have a ‘worn’ look to it. We left many gaps and wanted only to fill the gaping holes and to make the entire house seem uniform in its’ ‘old world’ floor appearance.

One year later, however, the filler has separated in several areas, causing an open space for debris and dirt to land. The floor had 2 coats of Poly, but these gaps do not appear to have any poly stopping dirt from entering into the cracks.

My question: The floors still look great and we like them to look old and worn, but we wonder if these gaps are going to soon cause problems or if this is a refinishing issue that should not have appeared so soon. Is there something we need to do, like apply more poly, or is this just typical wear for wood flooring?

A: The only wood filler (I know of) which makes boasts about not cracking out is Timbermate. As robust as this product is, it also can separate if there is shrinkage of the floor, which is what it sounds like has happened to your floors. This has nothing to do with the sanding-finishing job that was done. You might want to buy a colour match tube of Color-rite filler/caulking to try. Polyurethane is not a gap filler.

How do you fills gaps in laminate floor?

Q: How do you fills gaps in laminate floor? There are gaps between the boards in my laminated floors.

A: There really should not be any gaps between laminate if it is a decent product to begin with. There are all sorts of wood filler on the market to choose from. It probably won’t look great. But you can fill gaps in laminate flooring with them. If there are not many gaps, consider a tube filler product such as Color Rite.

Filling gaps in pine floors and planks

Q: We have pine plank floors in our century home and they all seem to have developed gaps up to 1/4′. What do you suggest to filling gaps in pine floors, so all the misc. floor things (dust, etc.) don’t buildup?

A: You might consider a product such as this:
You no doubt will have to tint it to get it to a close enough colour to match the pine floors.

Similar Q: Is there a product that will fill gaps between the long planks for a polyurethane covered floor, that can be applied to a large area? Using wax sticks seems like it could take days to apply. I’m wondering if a colored paste wax might do the trick? Any help appreciated.

A: You could apply a product such as from Final Touch with a putty knife or trowel. You would have to wipe off the residue from the finish before it dries with a damp cloth, and you would have to apply stain or finish to the gaps after it dries.

Gaps developing between some boards

Q: I have hardwood installed throughout my home (maple 3 inch). Lately, I noticed some gaps between some boards. Maybe 1/8 inch or less. I have air exchanger installed. What could be the cause of these gaps? Our home is 1-1/2 years old.

A: The humidity levels are too low. Common problem in winter. In cold climates I would try to keep the RH in the home near 40% RH.

Similar Q: Unfinished oak flooring was installed in our home a few years ago. Sanded and finished on site. It now shows cracks at the end of boards (not down the side). Is this from a lack of humidity?

A: Difficult to say, because wood flooring usually expands and contracts side to side, across the width of the floor. Though in the case of quarter sawn, it expands and contracts up and down. Shrinkage and hence gapping does indicate a lower moisture content in the wood compared to when it was first installed. If the shrinkage is more severe the top coat finish may stretch and fracture making the gap more obvious.

What is “checking”?

Q: I hear our new engineered hardwood floors are ‘checking’ everywhere. Though I’m not sure what checking is — please describe and is this normal?

A: I wouldn’t have expected an engineered floor to do this. Has a glossary of terms under their FAQ section which explains what ‘checking’ is. What species of wood is this? Another related site mentions some exotic species and the need to make sure the wood if properly dried or checking could occur:

Further, I have a wood dictionary which defines ‘checking’ this way: a lumber defect caused by uneven shrinking of the wood during drying. A checked board has splits which develop lengthwise across the growth rings.

Is it possible that this product was purchased from some far off place such as…let me see….China? Did the installers take moisture readings of the product before they started installing? If it had abnormal readings for whatever reason and then started drying out after installation perhaps this may have caused the problem. However, in that severe scenario, I would also have expected separation between the boards themselves. I think the manufacturer should send a representative to have a look.

Crack along a board in kitchen

Q: I have a new crack along the line of one board in the kitchen (along the seem- between boards). It’s uneven and seems to be getting worse. What would cause this?

A: Perhaps there was a spill there and water got between the boards, curling or cupping slightly the edge of at least one of the boards. Just a guess.

Follow-up Q: Thanks for getting back to me. I considered this as well. How would I go about fixing?

A: I would let it sit for a while and see if it corrects itself.

Gaps between hardwood planks

Q: I had my 30 year old oak floors redone. There were some areas were we had removed a fireplace mantle where the wood was put in new. They sanded and applied 3 coats of the Glista (scary after reading about it on your site, and to boot, they used no respirators!) I just noticed today that there are small cracks between the planks where the has now separated, gaps between hardwood planks. Can this be repaired by reapplication? Will they have to redo the floor completely? The old coating sure didn’t show separation before so what’s up with it pulling apart now? Was it the flooring guys not knowing what they were doing?

A: I think you need to add some moisture to your home climate. That is why the repaired areas are shrinking.

Follow-up Q: Would that be true for the boards that weren’t replaced? We are in Hawaii, so I didn’t think about the moisture..

A: I may have misunderstood your comments. I hope not. I thought you were saying the entire floor was developing gaps. Am I correct to assume it is just the new wood which was used for repairs? If that is the case, the guys should have checked it’s moisture content before using it to be sure it was close to that of your existing floor. If it was above normal, 7-9% it would shrink as it starts to shed the excess moisture.

Second follow-up Q: Well, yes it is by where it was repaired, but then it is in places where the floor wasn’t repaired too.. that’s why I thought it was weird. It’s just some places in the middle of the floor away from the repairs. It has been somewhat dry, so do I just wait for the expansion to fill the hole or do I need to reseal?

A: I would try to increase the humidity a bit but not apply more finish. That really won’t solve anything. Come to think of it, I need to get a humidifier myself. My hygrometer has been showing me readings of less that 30% RH, even down to 27%. Far too dry.

Related Q: We purchased an 8 year old waterfront home in April 2012. It had approximately 1000 sq ft of hardwood floors, which were cupping in places, finish worn off or thin in others. There were some spaces/cracks between some boards in the worn areas. We live in an area of high humidity in the winter. In the fall, just before the rains started, we had the floors sanded and finished with three coats of Swedish finish. During the last month, there have been increasing loud snapping or popping noises from the floor (we think), like someone dropping a number of heavy magazines or large books flat on the floor. In addition, large cracks (less than a dime width?) are appearing between a number of the boards. The noises appear to be more at night. We have the HVAC set at 70 during the day and 68 at night. We assume this is a humidity problem, but too little humidity in the middle of rainy season is curious? We have no humidifiers or dehumidifiers. Is there anything we could do?

A: Being a waterfront home, my guess is the floor cupped because it wasn’t properly acclimated before installation. It does sound to me like the popping sounds are from the boards shrinking during periods of low humidity. Swedish finish is a very hard coating. I don’t know how much it stretches but likely some of it has seeped between boards and dried on top of the tongue. If the boards shrink (a gap as thick as a dime would be considered normal, not large) something has to give and I think it is the sound of the finish breaking it’s bond between 2 boards.

I would suggest buying a hygrometer to monitor the humidity levels in the home. They are fairly inexpensive. Other than trying to control humidity levels within a range, I think you really are just looking at time to solve the issue unless cupping returns. In that case you are looking at another problem and another cause.

Follow-up: No cupping evident since we had them refinished two months ago. We will watch the cracks expand and shrink for a year and then decide what to do! We will learn to sleep through the pops I am sure! Humidity hovers around 40% + or – depending on outside temp and the furnace activity.

Edges raising in centers of laminate boards

Q: We had a laminate floor fitted 6 months ago, and some edges in the center are raising slightly. Also, there are slight divisions becoming apparent in some areas. Is this expected or should I complain to the fitters?

A: This type of flooring is supposed to be more stable than solid wood. Not all are created equal. what you describe is usually a symptom of excess humidity swings. During installation, a gap should have been left along walls to allow for any expansion. That may be an issue here as well as the product you had installed. I wouldn’t consider it normal or desirable.

Fill gaps with fiberglass?

Q: I live in Singapore and my house has hardwood floor strips (Balau wood from Malaysia). One year after installation there are visible gaps between the floor strips (tongue and grove) and the putty used to cover them keeps coming out when vacuuming the floor.

The contractor suggested we fill the gaps with fiberglass and re-sand after staining: is this practical? I’ve see you suggest a different kind of wood filler, but not fiberglass. Would fiberglass be a good solution? Another contractor suggested to use the same filler as I have today (probably just sawdust and glue), as he says the wood has already shrunk to the max, and it won’t come out… Can I trust him?

A: If you are sure these gaps will not close up with increased humidity, then you need something that will fill the gaps and also accept stain. I don’t see fiber glass doing that. You would be better off using a product such as I found here. A moisture cure adhesive in a bottle which accepts stain, or take a look at Timbermate:

Would the cracks and small gaps show again?

Q: I have 2″ slat hardwood. Small gaps. I used 3 coats of B*** water based polyurethane 10 years ago. I would like to refinish the floor. I would like to use a thick high gloss like Marine varnish #13. Would the cracks and small gaps show again? If I put down enough coats, would the natural floor movement start the cracks between the slats again, or would it be a solid coat?

A: I don’t think I would use marine varnish unless this is a boat deck. If there is movement in the floor, the coating will eventually fracture on the board joints. Perhaps you need to take a look at a wood filler such as Timbermate.

Follow-up Q: (Attached close-up of an interior floor) So, the interior floors with 2″ slats, having some movement and no matter how thick the coating, will eventually crack? Would the Timbermate help in this case?

A: It depends how much movement there is. They say it won’t shrink, crack or fall out. I have my doubts. It is a more robust filler, for sure. But there are limits to everything.

Gaps forming along walls, after DIY install

Q: Recently I installed oak hardwood floors in my house. I used pneumatic nailer, but at the area close to walls I had to nail down manually, and I can see gaps between woods. How do I fix this problem?

A: As you got near the wall, each board and each row should have been pulled in tight, either with a pry bar or floor jack, if you are lucky enough to have one of those. Now, you would have to take up the rows in question and re install them tight, or fill the gaps with any commercial filler that will match.

Trying to fix iffy install job

Q: We are in the process of buying our first house and we have a couple questions about the floor. The previous owner put in some bamboo engineered hardwood flooring, but he didn’t do a very good job with the details (meeting toilets, sinks, trim, etc.), so we are thinking about trying to fix it. We think it’s a floating floor, but we’re not sure if it’s glued or glueless at the seams. Do you think it would be possible to take up the floor and put it back down? We’re going to carpet one room that currently has the hardwood, so we hope to use the wood from there as the extra we’ll need to fix the other rooms.

A: I haven’t seen any floating engineered bamboo with click joint yet. Only thing I can suggest is to try to remove a piece. Lift one edge and pull. If it comes apart, fine. If not, then you know the rest of the story.

Cracking filler in gaps of poorly manufactured floor

Q: Our house has dark Brazilian Mahogany hardwood floors. Unbeknownst to me, last year, at the time of purchase, the floors ranged anywhere from 4 1/2 inches wide to 4 2/8 inches wide. Where the boards don’t match up, some kind of gap filler was used. However, over the course of the last year, the filler has been falling out of the gaps, leaving unsightly gaps in the boards, sometimes as wide as 2/8 of an inch. This has occurred particularly in the higher traffic areas, but it is occurring all over the main floor of the house. In addition, where the filler has not fallen out it has cracked, leaving zig-zag looking patterns in the filler. I am at a loss. Is there a product that can fill the gaps that have lost their filler? Will it prevent this problem in the future? Is it something that I can do?

A: Sounds like a poorly manufactured floor. There are 2 products you can look at. Timbermate makes great claims for their filler: Another product I like is called, I think, Colorrite, which comes in tubes with hundreds of colours to choose from. It is more like a caulking.

When your wood flooring is defective

Q: We put in hardwood flooring 7 years ago, 460 sq. feet. Not too long after, I felt the floor was not standing up. I called the company [makers of the wood], and they did send someone in. He said they would only replace a few boards. We didn’t bother– we we’re unable to at the time.

Since then the wood has gone from bad to worse. Again, we called the store we got it from, the company [there are now approx. 130 cracked in the wood, some quite large, that is not counting the other areas.] I might add the humidity is good, we did a do and a do not prior to having the floor installed. Also, I know how to look after a wood floor.

The company, after many weeks of working with them; sending out pictures, taping off the cracked, counting them [I could go on and on]… to make a long story short they now are not willing to do anything. They have given me every reason as to what they feel has happen [that it’s our fault]. I have had 3 home builders in and they all said that the floor should not have gone like this. The company did say they would have a sale rep. in our area in April and that he could have a look at it. Also, the first rep. that came in did a file on the floor and the company said that they could not find it. This is a lot of cash down the drain…

A: By “hardwood flooring” what species do you mean? What do you mean by the expression “not standing up”? “130 cracked in the wood?” Do you mean the boards are splitting, or do you mean there are gaps appearing between the boards? Your comments are so none specific, it is difficult to comment. For example, by saying “not standing up” do you mean the finish is wearing off prematurely? Is this a pre finished floor?

Follow-up Q: The wood was made by a company called M****. It is a natural birch,2 1\2 thick, semi gloss. The boards are actually spilling, one split is 8 1\2 inches long. There is no buckling, no gaps, etc. Some of the finish is prematurely wearing off. By not standing up; what I mean is, it looks like like we have had the floor down for 20 years, not 7 years.

A: No buckling, cupping, etc… So, there is no moisture issue. I would have to believe the flooring is defective from the factory and I would be chasing the manufacturer. There must be some sort of warranty on it.

Follow-up Q: Their answer was as follows; floor is moving, gaps in between rows, when floor opens and closes seasonally it creates a stress to the fibre of hardwood, boards crack. Since cracks are gray, it indicates to them that other products were used on the floor. This was their answer to us after some photos were sent to them. They also said that they cannot find a file on our first complaint to them approx. 4 years ago. They have a warranty of 10 – 25 years.

We have had three companies come in and look at the floor. They have all said almost the same thing: everything looks good, and the boards should not have cracked. Who’s right? The moisture in our home is good. I have only used proper wood cleaners on the floor.

A: In my opinion, slight expansion and contraction has nothing to do with boards cracking. A case where this might happen is when a floor is site finished with certain water borne products. Extreme movement of the floor caused by severe changes in humidity or moisture in the wood can cause a condition called side bonding and it has been known to break boards. Your floor is factory finished. Also, using poor products to “clean” your floor will not cause premature wear or finish failure. It could severely dull the finish. But it won’t cause the finish to wear off. If the finish is wearing off, they should stand by their warranty and replace the broken boards and worn areas.