# Painting a three season porch. Opinions please.



## Brian339 (Mar 15, 2009)

Tomorrow I will start painting a three season porch. It does not have heat. I will set up temporary heat so I can do my work but when I am done the heat will be gone.

What would you guys use?
Interior or exterior paints?

To be specific its mostly trim. The walls are made of MDF. Basically white trim and Navaho walls. Ceiling is natural pine, no finishes.


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## daArch (Mar 15, 2008)

Interior spaces that do not get ventilated to outside air should generally be painted with interior paints. It sounds like a three season porch is used as an enclosed room some times during the year. 

It's been told to me by a paint manufacturer (BM) that exterior paints can off-gas harmful fumes if used for interior spaces. Granted this was in the 90's and formulations may have changed. 

To be sure, I would call the paint manufacturer and ask if they have any cautionary advice about using their exterior paint for interior surfaces.


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## slinger58 (Feb 11, 2013)

I would use exterior paint. It's exposed to the elements (hot, cold, humidity).


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## DeanV (Apr 18, 2007)

How about an interior/exterior rated if worried?


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## NCPaint1 (Aug 6, 2009)

So its like a garage...but for people.

If its not getting wet from rain or snow, interior is fine.


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## Gough (Nov 24, 2010)

MDF in a space like that?? I don't think the paint is going to be the first thing to fail.


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## Brian339 (Mar 15, 2009)

Gough said:


> MDF in a space like that?? I don't think the paint is going to be the first thing to fail.


I dont understand?
My experience with painting MDF has always been positive. Why would it fail in a three season porch on the interior walls?
I would think its a bit more solid then wall board.


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## Susan (Nov 29, 2011)

Brian, it is enclosed, but unheated?


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## Gough (Nov 24, 2010)

Brian339 said:


> I dont understand?
> My experience with painting MDF has always been positive. Why would it fail in a three season porch on the interior walls?
> I would think its a bit more solid then wall board.


My point was that the MDF is likely to fail before the paint does. We've seen it start to come apart fairly quickly in areas with wide fluctuations in humidity. That's what will happen in an unheated space.

EDIT: if it's an MDF-H2 like Medite Exterior, that shouldn't be a problem, but there don't seem to be a lot of guy aware of the difference.


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## Brian339 (Mar 15, 2009)

Honestly I would be very surprised if the GC I am working with is incompetent. These guys know there stuff. I have all the faith in the world they are using proper materials. Thats all I can say about that.
Ill stick to my duty as the painter and be sure I do my part to avoid a failure.


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## Brian339 (Mar 15, 2009)

Csheils said:


> Brian, it is enclosed, but unheated?


That is correct.


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## Gough (Nov 24, 2010)

Brian339 said:


> Honestly I would be very surprised if the GC I am working with is incompetent. These guys know there stuff. I have all the faith in the world they are using proper materials. Thats all I can say about that.
> Ill stick to my duty as the painter and be sure I do my part to avoid a failure.


So you found the one:jester: 

I always thought that competent GCs were like UFOs: everyone talks about them, but who do you know who's actually seen one?


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## Bender (Aug 10, 2008)

I'd go exterior. If it was a kitchen I wouldn't want mildewcides in my paint, but 3 season? No problem.


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## Susan (Nov 29, 2011)

I've used both int/ext. Dependent on whether or not they use only screens in the summer. Yes, mdf swells when introduced to water..particularly at the ends, but a lot of the NC I've seen being built in the metro west region have what appear to be mdf exterior columns. Maybe they're fiberglass, idk, I'm not a doctor.


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## straight_lines (Oct 17, 2007)

You sure its not miratec?


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## Susan (Nov 29, 2011)

Who are you asking?


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## straight_lines (Oct 17, 2007)

Both of you.


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## Susan (Nov 29, 2011)

I don't know. Wasn't painting it. Walk through. The same columns were used indoors at a few locations. Oil primer for each column, composite base and crown trim.


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## painter1986 (Mar 19, 2012)

SW Solo. Interior/Exterior. We've had good luck with it.


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