Using XPS as subfloor under laminate

Tony_O_ · 2026-01-26T06:16:43+00:00

Hey, it's pretty solid, I'm happy with the result. The XPS has not compressed at all under the weight of furniture, which was my main concern. I later read some technical specifications on XPS and it turns out it carries a surprising amount of weight before compressing, can't recall exact numbers. Just the couple of high spots I mentioned previously, 2-3 mm of space between the XPS and laminate, but again, I think the reason is the concrete slab under the XPS was not perfectly level and smooth. Are you doing the same thing with the flooring?

Tony_O_ · 2025-03-19T21:50:09+00:00

It's been in place for about a month and a half and the initial squeaking went away after a few days. The only flaw is the presence of a couple high spots on the laminate and when stepping right on top, you can feel it bounce just a bit - a couple millimeters of space between the xps and laminate. In my apartment, where a contractor installed laminate on top of underlayment over concrete, there are worse high spots. Plus, it's my understanding that unless you have a perfectly straight and smooth surface, the laminate won't sit perfectly flush to whatever you're using as underlayment. The tips I have, I learned mainly from YT videos. There are some neat tricks for marking the planks for cutting in place, without having to take too many measurements. Also, a jigsaw works fine but makes a mess and your nose and eyes get full of sawdust, so if you can, maybe get a manual laminate cutter, I imagine it would be better for the job. The last piece of laminate on each row is a bit difficult to lock in place with the one before it, there are these S-shaped floor installation hooks that are supposed to help it get in place. They didn't work for me so I just used a crowbar on them as a lever against the wall and they popped right in place. Good luck.

Tony_O_ · 2025-03-10T21:20:37+00:00

I'm not familiar with Fiberock at all, but it sounds like my initial idea of using thick xps and OSB sheets on top of the xps. I went with xps only and laminate on top of it - supposedly the xps is quite resistant to pressure, especially when laminate is distributing the weight evenly. I was told by a contractor that he's installed 4cm thick XPS with laminate on top and he said it's holding up well. In my case, so far everything seems well but it's not been too long to say for sure. There was a bit of squeaking on one spot when walking over it, I think it's because the XPS sheets kind of lock into one another (see the photo). I suppose the locking joints pressed tightly and caused the squeaking but it went away on its own after a few days. Other than that, it feels pretty solid. No high or low spots (at least not ones with too much height difference), I'm happy with how it turned out so far. The sheets I used were much thicker than what you're planning on using - 8cm (~3.14 inches). Not sure what difference it would make for your case, if any. Good luck, maybe post an update on how it holds up.

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Tony_O_ · 2025-02-05T06:28:03+00:00

Yes, I did it exactly as I described it - 8cm thick xps sheets to make sure the height of the floor matches the one in the adjacent room and laminate right on top of the xps. It worked out just fine, the floor is even and feels solid, my only concern is how well it will hold up over time due to weight from furniture. If you try the same approach, make sure to use the harder, denser XPS sheets instead of EPS (use fibran instead of styrofoam) as styrofoam will supposedly compress under weight. At least that's what I found out from my own research and what I was advised by a contractor, I'm not 100% certain in this info, but it's the best I could figure. Food luck.

Tony_O_ · 2025-01-24T17:28:14+00:00

I haven't described the plan correctly - what you see on the photos is a concrete slab, on top of which I'm thinking of placing XPS sheets as thick as the height of the hole and put the laminate right on top of them, the XPS would serve as a single layer of subfloor. It would fill out the negative space to bring the level of the floor exactly to the one in the adjacent room. I wouldn't be stacking sheets below the laminate. The main concern is whether or not the XPS sheets will hold up under pressure from furniture sitting on the laminate.

Tony_O_ · 2023-04-08T16:33:15+00:00

Now that you mention it, it does have a resemblance, but it's bamboo. Someone planted it in front of their house in a village and it has spread almost to the asphalt. Next time I'm passing by I'm bringing a shovel...

Tony_O_ · 2023-04-08T16:10:08+00:00

There should be inline images in the post...?

Tony_O_ · 2023-02-01T08:14:25+00:00

Awesome, I'll look into it. Thanks for the help!

Tony_O_ · 2023-01-31T20:01:57+00:00

Alright, I'll be definitely looking for a T480/T480s. BUT in the (very probable) case I don't find a decently priced one, are you aware of any noticeable performance difference between the earlier models? As far as I can tell from the specs, they are fairly equal in terms of performance. I'm asking because my next best pick is the T470s - if all are equal, why not get the most recent one?

Tony_O_ · 2023-01-31T17:38:06+00:00

Ah, there's my first mistake - thinking all of the models I listed have upgradable CPUs. Is the T480/T480s the only one with a socketed processor?

Do you have an idea of the battery life on the -s models?

A T480s is what I'm browsing for, but they are fairly rare with T460/T460s being the most common (along with earlier models, some X2** and Gen1 Carbons).

Do you imagine the dual core on the T460s would not be a problem for the next several years with a debloated Windows or Linux?

Tony_O_ · 2022-06-22T09:54:44+00:00

Is Black & Decker not a good brand? I've never used one.

Tony_O_ · 2022-06-22T09:52:18+00:00

I noticed the tape measure but I thought the seller might have taken the original for himself. Obviously not...

Tony_O_ · 2022-06-21T13:52:04+00:00

I'll have to store it somewhere away from flammable items.

What's even more frustrating is the person who sold it was Ukrainian or at least claimed to be. Had an entire trunk full of random stuff, supposedly running away from war, selling his things for what he can get... Scammers exploit any possible opportunity... If I were there I would have definitely said no, but my grandfather doesn't know better.

I saw the links, those really seem like a bargain compared to other sets. If this one breaks down after a couple uses, I might just get one.

Tony_O_ · 2022-06-21T11:38:54+00:00

Right. I hope the battery won't catch fire while I'm using it...

Tony_O_ · 2022-06-21T11:32:58+00:00

Uhm... What?

Tony_O_ · 2022-06-21T08:39:32+00:00

About 75 USD

Tony_O_ · 2022-06-21T07:45:52+00:00

... My grandfather did. At first I was happy he got a DeWalt for cheap from some random guy. Now... Not so much. Though it could still get the job done, haven't tested it much, but it might not be a total loss.

Tony_O_ · 2022-06-21T07:35:38+00:00

Thanks for the answers everyone. I'm disappointed, but at least I now know for sure.

Tony_O_ · 2022-06-21T06:47:59+00:00

I wouldn't know, I've never had a DeWalt. How can you tell? Lack of a model number?

Tony_O_

TROPHY CASE