Mold worries after leaky toilet

Q: I had a master bedroom toilet leak and it caused a lot of damage to the carpets, door jams, baseboards, etc. It also got under my expensive, hand scraped hickory (4 years old) installed engineered wood floors. They are glued down on a concrete slab. The water damage experts said that there was still moisture under wood floors in the hallway and part of the living room. The floors show no signs of buckling or color distortion. My contractor said the installer did a great job installing them.

I am concerned about mold. Do you think I need to rip up the flooring and install new flooring? Or, if left undisturbed, are they okay as is? Will the concrete eventually dry out? I was told that if they are left undisturbed, mold will not cause health issues. Once it is disturbed by ripping up boards, then the mold can become airborne and can cause major health issues. Is this true?

A: If this was a floor installed on a raised sub floor then I would recommend ripping everything out because a large amount of water can seep and stay under there for a long time and take quite a long time to dry out. In your case, the floor is installed directly on the concrete with no space. I think the amount of water under there is minuscule and will transfer through the structure and evaporate. Keep in mind most needs a certain environment to grow. That would be warm and moist. If you have gone through this with no apparent damage to your hand scraped hickory, I’d sit down and enjoy a pint or glass of wine in my favorite chair and breath a sigh of relief.

Spot sanding water marks off waxed floor

Q: Hi. I’ve attempted to spot sand some water marks off the floor. Have retreated the areas with same wax as rest of floor, but they appear darker now. Do you know what I’ve done wrong?

A: If this is stained wood or tinted wax perhaps you used too coarse of an abrasive, thereby opening the surface of the wood more than the surrounding area. I think I would have used some fine steel wool and a tiny bit of mineral spirits.

Poly lifting where dog peed on floor

Q: We have a satin finish on out oak floors installed 2 years ago. Recently my dog peed a puddle and it sat for maybe 3 hours before we soaked it up. Was not yellow pee she just can’t hold her water long anymore – now that it’s up. The seams in the poly have lifted and it is not smooth any more to the touch. Is this normal? I spoke to my sister who has 2 dogs and lots of accidents on her satin poly finish and she said it just beads up and floor is fine. Even when she does not see for a full day? Thank you in advance.

A: If any liquid sits in the middle of a board coated with polyurethane it will bead up, yes. However, it can still find a way below the surface along board edges and it sounds like this is what has happened with you. If these episodes become more common the uric acid will eventually start to degrade your floor finish.

Similar Q: My dog peed on my wood floor. It hasn’t stained but the boards are swollen and slightly lifted where she’s gone. Can this be fixed or does my entire floor need replacing?

A: I would leave it for now and see what it is going to do. Maybe it will settle down when it dries out. At worst a board can be changed.

Sticky film from rug

Q: I just moved. My new hardwood floor was left with a light sticky film from an area rug that the previous owner had. How can I remove the sticky residue? It is not thick, it is just slightly sticky and when light shines on it it looks like a light whitish film is on the floor.

A: I would think a polyurethane cleaner would work, provided that is the type of finish on your floor, not oiled or waxed. Poloplaz has their version of such a cleaner as do Basic Coatings, Boa-Franc (mirage) and Bona Kemi. Poloplaz also has an even stronger cleaner called tie tac.

Main level floor affected by basement flooding

Q: In August we had some water in the basement. The temperatures outside were outrageous, high 30’s with humidity in the 40’s. Once the water was abated the Insurance company aggressively dried the basement. There were 3-4 dehumidifiers and about 10-11 large fans. Immediately after the fans and dehumidifiers were removed I noticed that my engineered hardwood floors on my MAIN floor were starting to sound like dry timbers. It has only become worse over the past couple of months so I am not at all confident that it will “reverse” itself like I was told may or may not happen. The floors were only put in 3 years ago and this is a real P*@@off! Could this very well be from the amount of equipment used to dry out the basement? The kitchen is right off from the basement and it somewhat open concept. The kitchen opens to the dining room which is open concept to the living room, which is where the majority of the floor issues are. Thanks.

A: I have a few questions: exactly how much water did you get in your basement? What is the flooring down there? Do you have a raised sub floor? Is the engineered flooring glued or nailed down? Have you noticed any humps, gaps between boards or cupping where the edges of the boards are raised?

Follow-up Q: The basement had an even 4 inches of water throughout. All the laminate was ripped out. But the damage and my questions are regarding my main floor. After the drying of the basement, we noticed the main floor; engineered hardwood nailed down with high grade underlay, started to make cracking sounds when walking on it. Even the drywall coming up from the basement cracked from being dried out so aggressively.

A: Well having that volume of water being absorbed by the surrounding structure you will get expansion. Then as it dries out or equalizes there will be shrinkage. The nails or cleats used to secure your engineered floor don’t expand however. They may pull or stretch a tiny amount but after everything dries out you floor will not be as tight as it was before. The less gradual a round of this expanding and contracting is, the more severe will be the results. During this process, I think it may have been wise for the insurance contractor to be monitoring everything with a moisture meter.

Similar Q: I had my floors refinished on the main floor. Two weeks later the water heater in the basement flooded. A couple days after the flood, the hardwood flooring above the water heater area ruptured and cupped. Is this due to the moisture from the water heater flooding from below in the same area?

A: I would think it is caused by that. How long did it take to clean up the flood? This is unfortunate. The only thing to do with these cupped floors is to give them time to stabilize. Hopefully they might flatten out on their own. It would be a good idea to have a dehumidifier running in the basement until all moisture is removed. If you have a hygrometer in the area it will tell you what the relative humidity in the area is.

Follow-up Q: Thank you for your response. The dehumidifier took about 2 weeks to get all the water out of the carpet in the basement. That’s why I think the upstairs floors ruptured and cupped. On my house insurance, I’m having issues proving to them that my hardwood floors were damaged and affected by the moisture caused by the flooding in the basement and they require proof in order to include the upstairs floors that is cupped and damaged above the flooded area. What proof can I provide to the insurance company that the upstairs flooring was damaged due to the flooded floors in the basement?

A: Contact the National Wood Flooring Association. They have inspectors fully trained who will come to your house for an inspection and write up a report. A number of years ago I was installing oak flooring on a main floor of a very old house and I found out that they were having a new concrete floor poured in the basement while I was installing this hardwood. I was very concerned about the volume of moisture that would be hitting the subfloor I was installing the oak onto. They stapled plastic sheeting to the bottom edge of the floor joists in the basement before pouring the cement.

Water softener overflowed onto laminate floors

Q: My water softener overflowed 26 gallons of water onto our laminate floors. We cleaned up the water and ran a dehumidifier and fans. The flooring covers about 800 square feet of our downstairs. However, the water ran under the laminate and when we took the vent covers off of our floor and felt underneath it was still wet, and that’s across the room. The flooring is resilient grip strip plank. There appears to be no damage to the floor above but we don’t want mold growing under the floor. Will the water dry up on it’s own with a dehumidifier or do we need to replace the whole floor?

A: Can you take the floor up without damaging it and keeping each piece in order? It will have to come up or it will take a very long time to dry out the area under it and you will end up with mold. That is quite a bit of water and it has to go some place. The way it is now, it is mostly locked in under that floor.

Whoever put the carpet in glued it down

Q: The house I bought has old carpet in the bedroom. I lifted the carpet and found hardwood floors. The problem is that whoever put the carpet in glued it down! The carpet comes off easy enough, but the underpad is glued to the floor. The carpet looks like it is 20-25 years old. How do I get the glue off the floor? Do I have to sand and stain the floor? Should I just by a new carpet and cover it up? Help!

I am wondering what kind of fool glues carpet down over hardwood?

A: Someone who doesn’t understand the value of a wood floor and hasn’t a clue what they are doing. Sounds like a description of quite a few (unqualified) DIY persons.

The only practical way I know of to remove this is to sand it off. I would recommend a professional. You will have to decide beforehand if the floor is thick enough to take an aggressive work out, which will be needed. Also, how tight or how many gaps are in the floor? If there are a lot of gaps, it is unlikely you will remove the adhesive from between the boards. Carpet is a cheap, temporary solution. If it seems ill advised to try to sand this floor, removing it and installing a new 3/4 thick floor is the long term solution.

Related Q: We tore up our carpet to find that we have nasty yellow/tan glue over our hard wood floors. We have scrapped, planed, and started to use some paint thinner. Could we use a drum sander with 16 grit paper to remove this glue?

A: You know about 16 grit sand paper? Well yes that would be the way to do it. I’ve done my share. Keep in mind the thickness of the floor can help determine if doing this is worth while or not. By thickness I am particularly referring to the thickness from the top surface of the board to the top of the tongue and groove. If that gets thin the wood will start splitting.

Follow-up Q: I’ve spent many hours crying over this project I really wanted.

We attempted 40 grit and it gummed up. So I didn’t know what we should use. They are original hardwood floors, I will check the wood depth in the vent. What is a good “thickness” that 16 would be acceptable. I hand planned all the glue off in the dining room. I don’t think my arm can handle the massive living room.

A: You may have wanted to hire a professional for this job, but you are into it now. If this is old style strip, you only have 3/8 or half inch from top to bottom. The wear layer is much less than this. If you start seeing nail heads appearing on the board edges you are going to be about done with this floor. If it is 3/4 thick you should be good. Sometimes people do this sort of glue down over hardwood because the floor is in really bad shape. other times it is because they don’t have a clue what they are doing. Hopefully in this case it is the latter, not the former.

Floors popping after nearly 5 years

Q: My Shaw engineered floors have been down 4.5 years, and one area recently started to pop when walked on. It spread to 4 boards. Then there are two pops under my oriental rug. Then one board in the bathroom started, and finally an area of 3 or 4 boards in a hall. The floor guy is mad at me because this happened! Why, you might ask, as I ask? Apparently he doesn’t know what to do. The floor under the pops feels spongy when walked on. The floor is on concrete, glued down. Having not been educated on laying floors of any kind, I’m at a loss also.

I read a lot on your website, will that injectable glue work on these floors? An independant inspector came out and just said it was not the manufacturer’s fault. His report was so vanilla, that one could make it mean anything or nothing. The installer paid the 150, and he thinks it means that he is in the clear. Can I expect this to continue to happen in other spots? This occurred about 3 months ago, and I’m wanting to put my house up for sale, but wondering if no one will want it due to these 4 areas of popping wood. Can you help me? I live in upstate South Carolina. We did have heavy rains this past winter,but there is no smell of moisture in my house and I use no humidifier. The report said that the inside conditions were 55% RH and 70 degrees F. Moisture presence in the flooring measured with a Tramex moisture meter averaged 15.6% with 24 total checks made.

A: Clearly something has changed in the environment. It sounds like your floors have swelled and this side pressure is causing the floor to raise in these areas. 15.6% moisture content in the wood I consider high and not normal. Is it possible you have a slow, hidden leak someplace and moisture is creeping under the floor? The moisture level in your floors will need to be corrected before you can think of going to other measures such as injectable adhesive. Did the inspector think this reading was fine?

Follow-up Q: Thank you so much for answering. Do you mean a leak in a water pipe under the floor? What do I do to find out? The areas where the popping occurs are far apart. Each place involves 1-3 planks. There are 4 places, rooms apart. The inspector was not useful in my opinion. He was working for the guy who laid the floor, so it seemed to me he thought it was the installer’s lack of preparing the floor, but didn’t have the courage to say so. He kept speaking about how an installer had to prepare cement because it was never even, but put nothing of the sort in his report. What do you think should be my next move? I want to sell in a few months, and need to have everything in good condition. Thank you again. There is no change in the appearance.

A: I would contact The National Wood Flooring Association and see if they have an inspector near enough that he would come out for an inspection. They will give you an impartial, honest appraisal. It could be that for some reason he didn’t get real good grab between the adhesive and floor. But why is this all happening now after 4 years? The spongy feel in those areas and the what I consider a high moisture level reading tells me to suspect something else.

I’d be interested to know the results if you are able to get one of the NWFA inspectors out to look.

Second follow-up: Good morning, I have consulted with my water provider, and there has been no change in the amount of my water usage, thus no indication of a water leak under my concrete. That’s a relief. Still eager to hear where you think I should start.

A: I don’t know what you should do at this point. As I mentioned in my last email, if you received it, the inspector who was there is NWFA certified. His report seems to indicate concern with the high moisture readings in some areas, 15.6%. He mentions in his report that some boards should be removed to check the concrete. I think you should phone him and discuss his report. He is certified. He has inspected the job site.

Third follow-up: Thank you, so much. I’ll let you know how things turn out, as you requested.

A: How old is this house?

Fourth follow-up: It is a 20 year old, middle unit of 3, one floor, brick condo. I have lived here 12 years. Previously it had carpet. The other owner spent more time at the beach than in the home, so it was not used much the first 8 years. No one in the units next to me have had problems with moisture. One still has carpet, and the other one has some type of laminate (Pergo?) that has been there the whole 20 years. The floor is still in excellent condition.

Only person in our neighborhood who had problems is one lady who had her Mohawk floor, mine is Shaw, installed just before I did, by the same company who did my floor. She has had the same problem. They cut into her floor and replaced the boards. I haven’t seen it, but she says it is bad looking. I will try to go by to see it soon. No one else in our neighborhood used the same company that we did. Both of us are widows. The other lady is older than I, and not very well. I think she just gave up. I haven’t asked her what they told her was the reason her boards were popping.

A: Interesting. I can only do so much. I’m far away. It seems odd your floor was down without any issues for several years and now you have these areas with high moisture content readings. I don’t see the point of changing the boards unless the cause is identified. How is the floor being cleaned? Is a lot of water being applied? Do you have a cleaning person helping you?

Last follow-ups: I use only Shaw hard surface cleaner which is what Shaw company told me to use when I contacted them soon after my floors were installed. Thank you again. Since I don’t really have any faith in my installer and it appears not to be his error? Where do I start to get to the bottom of the issue. Plumber, builder or who?

Thank you so much for your time. This has been very upsetting to me, and the installer has been so rude. He is so scared that it is his fault, that he would not help me get to the bottom of this. I definitely will do as you have suggested. In case I misunderstood the anything in the inspector’s report, I am including it in its entirety. After your response, I will begin my quest, and will definitely let you know what the final verdict is.

I appreciate your help very much.

A: Okay, this inspector is NWFA certified. He basically is concerned over the same issue I mentioned. High readings for moisture in certain areas which would require removal of some of the boards to expose the concrete and then test the concrete. My question is why it took this long for this issue to appear. Perhaps something has changed around the building? A drainage issue? I don’t know. The excessive moisture appears to be the immediate problem.

Can a roof leak cause cupping in a hardwood floor?

Q: Hello, is it possible for a roof leak to cause cupping? For the water to go down through the walls and get under the floors? We have cupping floors and that is the only possibility for water damage. Thanks!

A: Yes it is very possible. I’ve seen that happen more than once. All I can suggest is locate and fix the leak and run a dehumidifier to dry out the floors. Once in a while they will actually flatten out. Unless you suspect a lot of water under the floor the best thing to do is leave it alone and let it dry out completely.

Follow-up Q: Thanks so much for you response. Do you have a suggestion for how often and how long to run a de-humidifier without over doing it? Thanks!

A: I don’t think you can over do it running a dehumidifier. Having a hygrometer in the home can be helpful. It gives a reading of temperature and RH in the room. This time of year an RH of 45-50 is normal. I installed unfinished oak once in a very old house in Toronto. This place was on the edge of a ravine, surrounded by trees. One day it was mid 90’s and the humidity level was over 90%. In a panic I told the home owner, who wasn’t living in the house yet, to bring a dehumidifier fast before it started raining inside the house, lol. I wouldn’t expect you to have a moisture meter but if you had one you place it on the floor and it will tell you the moisture content of the wood. 6-10% if fine. 15 and up is not good.

Splits on edges of board due to wear

Q: We recently had some oak engineered flooring installed and have noticed two small splits at the very edge of one of the boards. I think they have steadily gotten worse as they sit right near a door threshold, which is a high trodden area. Can it be repaired or will we need to replace it? Thanks.

A: You could use some colour matched wood putty to simply mask the cracks. A good product is Color Rite. Comes in tubes. Dozens of choices and easy to work with. If the split get serious then of course the board will have to be replaced.

Humidifier flooded floor

Q: We left a humidifier running for 8 hours overnight and in the morning the laminate wood floors were soaked. We cleaned up all the water and there appears to be no damage. Should I still use a de-humidifier to dry it up?

A: If you had a pinless moisture meter to check the floor directly that would help but I know that is unlikely. It wouldn’t hurt to run a dehumidifier for a day and see how much moisture is captured. It is positive that there is no apparent damage at this point as I would expect the cheaper products to have curled edges soon after getting soaked. Some of the good laminates such as Torly’s claim water can be across the seam of at least some of their floors for 5 days without any water penetration into the product.

Touching up stain in dent

Q: We have dark walnut stain on oak floors, with Swedish finish. A dropped tool put a small dent (half dime sized) that broke through the finish and now the light wood shows. I can live with the dent but need to make it match the rest of the floor and touch up the finish. I’m a pretty good DIYer. Best course of action?

A: That sort of thing is annoying, isn’t it? It happens though and they are wood floors, meant to be walked on. Hard to believe this tool impact actually also removed the stain but that is what it sounds like you are saying. You could dab a touch of the stain on the spot. Additionally there are pre mixed tube fillers such as Color Rite which come in hundreds of shades. If you can find a good match then smooth some into the dent and let it set up. Re-apply if needed. Next day you may want to add a drop of the finish on top of this to harden it and help blend the shine. Hope that helps. I don’t know how Swedish finish is these days but way back it really smelled bad.

Removing soft putty from nail holes

Q: I used wood putty instead of a sandable wood filler on some shelves that I built and now I find out that the putty does not get hard. Ouch, my stupidity I know, but do you know of a way to remove the putty from the nail holes so I can then use a sandable filler and paint over? Thanks in advance.

A: If you are painting over the putty would it matter if it gets hard or stays soft? I would use a nail the same size as the hole to remove the putty if you wish.

Old floor popping sounds during the night

Q: I know that the question of wood floors making popping sounds during the night has been asked; however my white oak floors are original to the house built in 1948. I did have the floors refinished about 6-7 months ago with water-based finish and like the others, the popping only happens at night without anyone walking on them. I’ve had this house for 17 years and it’s never done this before. Do you think it’s still humidity related? I live in Southern CA so it’s pretty dry here. Thanks!

A: As companies have been forced over the years to develop water borne coatings they soon discovered they also needed to develop special sealers to prevent an issue called side bonding. These coatings are more brittle and rigid than oil based finishes and thus don’t stretch as much with movement in the floor. I suspect the noises you hear are the finish stretching and cracking along the board edges or between boards where it slipped into tiny gaps between boards. Once that has completed the noises should stop.

Sanding grooves visible after first coat

Q: After sanding and staining our hardwood floors we applied polyurethane, clear semi-gloss. As the first layer started to dry we noticed the floor is covered with the sanding grooves! What can we do to make them not or less noticeable?

A: I’m surprised you didn’t see these marks as soon as you started applying the stain. Short of starting the entire process over, choosing the proper grits to use along with a proper preparation procedure, your next best bet is to go with a very low shine as a finish. The higher the shine the more unforgiving it will be visually. So, I would go with satin or even a matt finish. This will help hide and deflect attention away from the sanding marks.

Glue down hardwood floor separating at joints

Q: My parents had hardwood floors installed in their home a little over a year ago. They live in a home that is about 8 years old and the 3 rooms that had the flooring put in all had carpet in them previously, which was properly removed. Then the floor was levelled. This weekend the flooring started separating at the joints, in random parts of all 3 rooms, which are in different parts of the house. The installer is a friend of mine and he had never seen or heard of such a thing. The flooring was purchased from my work, and when I spoke to the decorator here she said that it has to be an installation problem. The installer knows he used the correct type of glue, but have you ever heard of a floor doing this after being down long? The house has no structural issues.

A: This floor is glue down? It sounds like the sub floor is shrinking and the glued down floor is separating at the sub floor seams. I’ve seen it only a few times in 40 years, even on very old floors. It stands to reason, the finished floor will react to what the sub floor is doing. I would put a moisture meter on both the finished floor and sub floor if you have access to that. They should be within 4% of each other. You may also check the humidity level by placing a hygrometer on the floor for a short time, say 15 minutes. I feel fairly confident the issue is the sub floor itself. What was used to level the floor? If water was added to the sub floor along the joints (I assume it is sheets of something) it may have expanded and then as it dried it shrunk.

Bowed flooring in front of refrigerator

Q: We have lived in our home for one year. When we moved in we had our red oak hardwood floors refinished. We also had our crawlspace treated so that it is clean and dry. Now, over the past 3 months of summer, an irregularly shaped area of flooring has become bowed, starting with a couple of feet and spreading to become about 20 sq ft. The area is in front of the refrigerator and extends into our pantry, which is beside the refrigerator, separated by a small drywall. We have had the appliance repairman out (fridge works fine), the crawl space guy out (no evidence of moisture anywhere), the plumber (no evidence of leak), the foundation expert (nothing). All meter readings say floors read at 8% and crawl space humidity is very low and dry. Floor guy ripped up boards in pantry. We found evidence of staining on subfloor! However the color of the floorboards is yellow, not black or dark as would be expected from water. We are assuming (?) there has been some previous spill, oil-related (?) that seeped into subfloor. Either way we are having floors replaced in the area, but I’m asking: do you agree with this assessment, and is there anything we should do to prep the subfloor before laying new floor over it? It appears dry now.

A: Cupping is caused by excessive moisture imbalance on the underside of the floor. As soon as I saw the sentence ‘in front of the refrigerator’ I thought ‘oh no. his ice maker is leaking’. Or the pan under the appliance that catches defrost water has over flowed.

The only advice I can offer at this point is that ‘appear dry’ isn’t enough. The sub floor and new floor need to be checked with a moisture meter and not be more than 4% difference between the 2, with 7-9% generally considered normal for hardwood such as oak. Have the new flooring in the room for a week before installing.

Dark spots on floor hot to touch

Q: We bought engineered bamboo hardwood flooring in February and kept it in the house until it was installed in March. It was glued down with the glue that the store recommended. Now dark spots are showing up in certain areas of the kitchen. Bubbles are now appearing on the darkened areas and the wood is hot to the touch. This part of the floor does not have a full basement, but does have installation and subflooring. There does not appear to be any moisture anywhere. What could be the problem?

A: I’m not certain what is going on. That you say the spots are “hot” may be a clue. Is there some type of reaction going on between the adhesive used to install the floor and the adhesives used in the floor itself? I would definitely be calling the company you bought the floor from and have them come and inspect it.

Repairing caster wheel dent

Q: I have a wood floor that looks like hand scratched with a gloss. We are just moving into this home. They had a pet gate at the top of the stairs with a caster wheel that put a half circular rut into the floor. What is the best way to not make it look so noticeable? Touch up marker, sand it lightly, polyurethane?

A: You mean hand scraped? It depends how deep the ‘rut’ is, but I would try all the things you mentioned. The next step would be to scrape all the finish off the affected boards and do them over. As a side note, it is my view that hand scraped floors should never be finished with polyurethane but you have to deal with what you are inheriting.

Hollow spot in floating floor

Q: I wondered if you could suggest a fix please, for our new kitchen. The original floor was concrete, and this had levelling compound put on top, a floor fitters request. All looked okay, but there is a hollow spot in floating floor (now it’s all fitted where it creaks when you step on it, you can see the wood dip when you apply weight). Obviously it’s a little hollow in that area. The floor is floating engineered wood, sitting on a moisture barrier/underlay. As the floor is not glued down, can I still inject adhesive though the board and wait for it to cure effectively “filling” the hollow rather than gluing it down? The hollow spot is only a few boards in, so I may do it from side rather than drill down. Or is there a better way? (The fitter is no longer with us, floor is a year old now..)

A: I think you’ve got the right idea for an easy fix. I believe Bostich has such an ‘injectable’ adhesive. I’ve never used it but I would think it expands as it cures, thus filling the void. So, if you can do this without drilling a hole, all the better.

Similar Q: Why are there air bubbles in the glue that I’m using for our bamboo floor? I recently installed my living room and now when you walk on it, you hear popping.

A: It’s possible that you didn’t get complete grab of the adhesive between the sub floor and the bamboo. This could be caused by something as simple as a slight depression in the sub floor. It’s probably best with a glue down floor to go over the floor with a weighted roller as you work. If there are hollow spots here and there you can use an adhesive syringe after drilling a tiny hole. This will expand in the cavity under the floor and stop the movement. I believe companies such as Bostik Findley make products like this.