# Using MDF on an enclosed porch?



## LearningAsIGo (Mar 8, 2011)

I'm planning on creating shaker style wainscoting for my porch and was thinking about using MDF because it would be cheaper than real wood and I will be painting it anyway. The porch is enclosed and basically another room in the house but it does not have heat or air conditioning and I do live in New England. The walls are insulated but the ceiling and floor are not. I hope to insulate the ceiling at some point.

Does MDF not tolerate cold or heat well or do you just have to worry about swelling if it comes in contact with water?


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## LeeBarker (Aug 6, 2010)

My view is that your site would be considered exterior inasmuch as there's no heat. It's the edges of MDF that absorb moisture easily, and I have a hunch that in a few years you'd regret the decision.

Consider an exterior ply with a sanded face if you want to go to sheet goods.

Kindly,

Lee


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## CharlieM1958 (Nov 7, 2006)

I agree with Lee. A few dollars saved now will leave you kicking yourself later.


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## Loren (May 30, 2008)

My first reaction would be a no on the MDF in an exterior application
but then I remembered it is sold as a profiled siding material and 
has been for many years.

If I were you I'd research the durability of the siding and ask
yourself if you want to take a chance.


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## reggiek (Jun 12, 2009)

MDF does not tolerate moisture - it will swell and turn into mush….exterior ply or OSB would be a better choice….Another way to go is to use pine or Douglas Fir as it is cheap (or any other cheap wood would work as being painted can give it enough protection from the elements) and when painted can be fairly tolerant of the moisture ….White Oak, Redwood or Cedar are typically the go to outdoor woods.


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## BillWhite (Jul 23, 2007)

There is an exterior grade MDF that will work just fine. Look it up on the net. I have it on the exterior columns on my home. As long as it is not submerged…....
Bill


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## LeeBarker (Aug 6, 2010)

I had forgotten about the exterior MDF too, Loren. A friend put a hunk in water and it was there a couple weeks and did not even change shape. 3/4" thick.

And that's all I know!

Kindly,

Lee


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## reggiek (Jun 12, 2009)

I have heard of an exterior grade MDF, but have only seen it made into siding (expensive yet looks cheap…and tacky) I imagine they would have a bonding agent that is waterproof….and hopefully UV proof also. I do not know the price of it….but I still think you would be better served by an exterior solid wood…like plywood or such….because even if the binding agent is waterproof…the wood particles are not…sooner or later it will break down….but that is more a personal preference….I am not a big fan of MDF…I pretty much only use it for jigs.


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