Rookie Reno Lessons: Prepping Subfloor for Flooring Install

March 13, 2019

Modern Traditional Living Room - The Adored Abode

Today marks the start of a new blog series – Rookie Reno Lessons. When we bought our home almost 3 years ago we were (and I would say we still are!) renovation newbies. Over the course of 3 years we have tackled many projects in our home and with each project comes a few new lessons learned, things we would have done differently, and things we wish we would have known ahead of time.

I thought by starting this series and sharing the things we, as figure-it-out-along-the-way DIYers, have learned so that you can learn from our mistakes! Each post in this series will cover a specific topic and today’s topic is all about making sure your subfloor is the in the best shape possible for installing flooring, whether you are installing new flooring or hiring the whole process out (I’m sharing good tips and pointed questions you can ask your contractor if you’re not doing the work yourself)! I’ll admit, this isn’t the most exciting topic, but so far it has been my biggest renovation regret and because of that I thought it would be the best “lesson learned” to start with.

For those who are new to installing hardwood floors, the subfloor should be smooth and level so the new flooring going in will also be level, with no humps or bumps. Especially with hardwoods and tile this will help ensure there is no cracking or breaking from stress the floor is under due to an unlevel subfloor.

*We had solid hardwood flooring installed, but the lessons we learned really apply to any type of flooring.

Upstairs Hallway Progress - The Adored Abode

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I shared a few weeks ago how our hardwoods are holding up over 2 years since they have been installed. The short answer is: wonderful! I cannot rave about the flooring itself enough. However, in many areas of our main level the hardwood floors are not level, not even close.

Here’s Why This Happened (The Process)

Living Room Before - The Adored Abode

We chose to tear our existing flooring (carpet mainly, except for tile in the entryway and linoleum in the hall bathroom) to save a little money of the flooring install. This was one of the first projects we tackled in the house and we knew it was going to be expensive, so we were most comfortable with saving where we could. We ripped up all the carpet, tack strips and staples (ughhh the staples!) from our living room, master bedroom, dining room, and den. It was when we ripped up the carpet we really started noticing the subfloors were not level at all.

Hall Bath Before - The Adored Abode
Hall Bath Before - The Adored Abode

We (really just Nathan since the bathroom is so small) also ripped up the linoleum in the hall bathroom, which Nathan said was super easy with a pry bar and a rubber mallet.

Entry Tile Before - The Adored Abode
Prepping for Flooring Install - The Adored Abode
Entry Tile Before - The Adored Abode
Entry Tile Before - The Adored Abode

Then we moved to ripping up with tile in the entry way. It was painted terra cotta tile that had a pretty design, but the brown and pink coloring was not our style. We found out the tile was installed on a sunken 3-inch bed of concrete, rather than cement backer board. After talking with several flooring experts this was apparently common in the 70s and 80s (our house was built in 1980). It was a complete pain and extremely dusty to rip up the tile and the 3-inch cement bed. We used a wrecking bar and a digging bar mainly for this messy job. After the removal of the tile and cement we then needed to level the now sunken subfloor with the existing subfloor, which our neighbor who is a contractor suggested doing by screwing in individual sheets of plywood subfloor (thickness depending on the depth the floor is sunken) until the floor was flush with the rest of the existing subfloor – using shims and shingles (as weird as that may sound – they are good for leveling the subfloor layers we had to install) to level it out as you go. During this process it highlighted even further how uneven our subfloor was.  The entryway connects to 3 different doorways; the dining room, the den, and the living room. At each of these doorways the subfloor was at vastly different heights so we really had to utilize the shims and flooring felt to make the entry flush with all connection points to the existing subfloor. For everything we installed in the entryway we made sure it had a flush transition to the existing subfloor. This was much more work than we bargained for and thankfully we had the help of our family along the way!

We took care of all the points of unlevel-ness with our entryway where new subfloor was installed, but since we were hiring the install of the hardwood we requested our contractor and his team make sure the existing subfloor was level. Spoiler: they really didn’t level any of the existing subfloor how it should have been leveled.

WHAT LESSONS DID WE LEARN?

Rookie Reno Lessons - The Adored Abode

Some of these lessons learned may seem obvious, but in the moment, when were still so new to figuring out this whole renovation thing they were not. So, if you’ve already learned some (or all) of these lessons the hard way yourself you are in good company! As you can see from the image above there is a rather visible bump, especially when you look at the stairs head on, at the right side of the stairs. This picture does distort it a bit and makes it look a tad more un-level than it is in person, but regardless, the bump is still there.

MARK EVERY UNEVEN SPOT YOU WANT ADDRESSED (EVEN IF DOING THE WORK YOURSELF)

We didn’t walk every inch of our subfloor where the hardwoods were to be installed with a level to clearly mark areas of unevenness that needed to be addressed. This would have been the perfect way to clearly communicate with our contractor the areas we expected to be addressed. I would even go as far as creating a floor plan map of the area you are having flooring installed and mark the areas of the floorplan that you expect to be addressed (in addition to physically marking the spots on the floor) and have your contractor sign and date it.

ALWAYS HAVE A WRITTEN CONTRACT WITH YOUR CONTRACTOR

We didn’t have a written contract with our contractor. This is an extension of #1, but we simply relied on our contactor’s word that they would “level” the subfloor prior to installing the hardwoods. We were so new to working with contractors at this point (and honestly, we are by nature very trusting people), but this is something I have done with every single contractor since. Establishing a written contract from the beginning doesn’t mean everything will be smooth sailing, but it definitely helps.

Level can apparently mean different things to different people. Our hardwoods specifically state that they should be within a tolerance of 1/4 of an inch over a span of 10 feet, meaning within any 10-foot range, there should be no dips or humps exceeding 1/4 of an inch. This is also the general guideline for most hardwood floors that are installed with a nail-down method like ours (according to the NWFA). Any good hardwood flooring install contractor should know this and adhere to it. Ours did not, and unfortunately since we didn’t have anything in writing stating our contractor should do this, so we really had nothing to go back on.

I am planning a whole separate post on working with contractors, but my number 1 piece of advice is always have a written contract.

WORK WITH AN NWFA CERTIFIED HARDWOOD FLOORING INSTALLER (IF CONTRACTING OUT THE INSTALLATION OF HARDWOODS)

If you are installing hardwoods make sure your contractor is NWFA certified. I did not even know this was a thing prior to seeking out a contractor to install our hardwood flooring, but having a contractor who is certified could help avoid some of the issues we ran into. 

DON’T BE AFRAID TO SPEAK UP (LOUDLY) WHEN SOMETHING ISN’T RIGHT

We noticed after day 1 of the hardwood flooring install that areas of the living room (where the install was started) weren’t level. When I say not level, I mean they have a 1/2 inch drop over the span of 2-3 feet, well exceeding our flooring’s specifications. I brought this up with the contractor and they said they “leveled it as best as they could” just using flooring felt and that existing subfloor was not level because the joists holding the subfloor up were extremely unlevel in areas and all the subfloor would have had to have been ripped up, the joists fixed, and then new subfloor reinstalled for it to be perfectly level. I communicated that I wish they had called us immediately when they noticed this issue rather than continue the installation. The contractor just kept saying they “did they best they could”. I felt defeated. We honestly didn’t think there was anything to be done at this point. They had already installed over half of the hardwoods (almost 1000 of the 1800 square feet) and it would have been a completely sunk cost to have them rip it all up and even more money for the joists and subfloor to be completely addressed. We decided to have them just keep going, knowing we were going to be living with unlevel floors. Had we known of the joist/sub floor issue sooner I would have wanted the install to stop. It honestly all goes back to not having a written contract with the contractor and not establishing good communication (i.e. ensuring they call us at the first sign of trouble) from the beginning.

Again, most of these tips really go back to how to successfully work with a contractor and I am planning a whole separate this, but I thought the tidbits of advice were worth it to share now.

Honestly, it’s a bit hard to write about this because it is still a sore subject and something I notice almost every day. Thankfully, over 2 years later our floors have shown zero sign of cracking, stress, or breakage. I’m telling you, our HARDWOODS are awesome. So ultimately, the only issue so far is that the flooring has some rather noticeable humps and bumps – primarily isolated to one corner of our living room, the landing beneath the stairs, and one side of the den. It’s obviously not the end of the world, but since it is something we invested a lot of money in it is pretty disheartening to know it didn’t turn out how we had hoped. I can say I took my own lessons to heart though – we hired a different (certified) contractor to install the hardwoods upstairs, we had a contract from the beginning, and we had excellent communication with the contractor throughout the entire process. I am happy to report that our upstairs flooring was appropriately leveled!

Have you ever learned any lessons the hard way when it comes to renovating or doing projects around your house? Let me know in the comments below – that way we can all help each other out!!

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2 Comments
    1. Hi Allie.

      My name is Titus and I’m interested in learning or having classes in concrete floor finishes.

      I want to learn how to apply epoxy,stucco and others.

      Pls advice.

      Kind regards

      Titus.

      1. Hi Titus – I unfortunately don’t have experience in concrete floor finishes. I would suggest looking to see if there are any helpful tutorials on Youtube (that is where we learn a lot!). Best of luck.

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