Does you guys call out pressboard attic walkways? It obviously isn’t as strong as plywood, but I’m not sure if I’m being too overzealous by recommending that it gets replaced. I’m imagining someone putting down a heavy storage container a little too hard and breaking through to the garage below.
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You could just footnote mention that the stuff bends under heavy load, and be done with it.
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Most definitely recommend replacement with proper material. That pressboard gets very brittle after a few years up in a hot attic. I know, I fell thru it once!
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Ah man, there ya go. Thank you! Hope it wasn’t too bad!
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I hooked my right armpit in a truss member, so I didn’t fall to the floor. It took about 2 years before I had full movement without any pain in my shoulder.
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I always call out substandard attic flooring or walk-ways.
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That looks like particle board and appears to be fairly thick and should not be a problem with 16" framing.
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A thin material can do the job if there are ample fasteners, like how thin sheets of aluminum can be formed into an airworthy airplane with about 10,000 rivets. I would be wary if the floor flexes significantly under load, meaning that the materials are too thin or there are not enough fasteners or both. The more the material flexes the quicker it will fail (becoming dangerous), in general.
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Damn, sorry to hear it. Maybe that was a relatively good outcome though…
Thank you gentlemen! I’ll err on the side of caution. It’s a 1989 so who knows how old they are.
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MDF (Medium Density Fiberboard) is not listed in the building codes or National Design Specification for wood construction. All the engineering properties needed to design load carrying capacity are not published, so in my opinion it should never be used as the primary load carrying member. Great for underlayment and miscellaneous projects.
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I was doubtful that MDF was designed to be walked on. Thanks Randy!
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I have mdf subfloor over plywood in my 1972 home. I think the critical part is “over plywood”.
Here are some examples of what I consider “substandard”
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MDF is an engineered wood composite that is similar to particle board, but is much denser and stronger than particle board.
If it is 3/4" thick like it appears to be, I would not worry about walking on it on 16". center. I know the capacity of those products in use.
I agree that it is not structurally sound and best material for attics, but all depends on the thickness of the material.
Attics often require a strong and compact structure to carry the weight of items in storage . Although MDF is heavy, it is not a common sight to see them as flooring options for an attic. This is because they are slippery and heavier than any other wood. Moreover, they are also more water-absorbent which may not be an ideal thing for many homeowners.
Depending on how it was nailed, secured, and supported, I would not necessarily call it out. But, I was not there.
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Yea, you’re right. Some of them actually felt safer than some of the plywood sections. There were a bunch of tiny plywood sections that butted up against each other on the same joist, so I didn’t trust it flexing too much. I stayed above the joists.
Thats another reason they’re bad in an attic. Plywood wont turn to dust after a roof/plumbing/evap coil leak.
The floor is just about every mobile home is MDF.
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particleboard
Mobile homes and manufactured homes, for many years, constructed subflooring consisting of a glue and sawdust combination referred to as particleboard.
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Particleboard has published engineering properties, which makes it possible to calculate its load bearing capacity. But if it gets wet it’s just a pile of wet sawdust.
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True, Randy, but if you have that kind of scenario in an attic, you have other problems other than being able to walk on.
Used mainly for furniture, underlayment and a substrate for counter tops. Not intended to be used alone as floor sheathing. I would mention that in my report.
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Mobile homes and hurricanes/floods do not play well together.
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