Porch Column Technique

[Dave]

I need to replace some fake porch columns this fall and am wondering what works for others. The current posts are 3/4" MDF rectangles with an additional box or trim girdle around the base and top. The original builder installed them and painted the exterior only, allowing the MDF to absorb moisture from rain or snow on the (concrete) porch surface.

I remember seeing quite a bit of discussion in Fine Homebuilding a year or two ago but I can't seem to locate those issues.

The plan I am considering is to reproduce what currently exists, but paint all 6 surfaces on each piece before assembly. I would appreciate any input.

Dave

[Steve]

I would NOT use MDF. I would use poplar. The base would be wolmanized and I would ventilate them top and bottom. Painting all 6 sides/ends would still be a good idea. Be sure to caulk all the joints prior to final coat of paint.

[Doug Miller]

Paint isn't waterproof, and MDF isn't suitable for exterior use. Painting all surfaces before assembly may delay the deterioration by a few years (or it may not), but it won't prevent it.

For the base, use treated lumber or some naturally rot-resistant species (e.g. redwood, cedar, locust, cypress). Use solid wood for the rest of the pillars. Poplar is probably a good choice; a rot-resistant species is not necessary here, but won't hurt.

If you build the replacements out of real wood, it won't be necessary to paint every surface before assembly.

-- Regards, Doug Miller (alphageek-at-milmac-dot-com)

[Leon]

If you column is rotting from the bottom, My buddy and I have repaired probably 20 of these columns in the last 4 years or so. We cut the bottoms off and build a decorative and more water resistant base from PT lumber. We use a floor jack and 4x4 to raise or support the porch so that we can remove the column.

[steveki]

[Trent©]

Use real wood this time, Dave. MDF was a bad choice.

Painting all the sides is a good idea...won't hurt. But painting the insides isn't all that critical. The outsides and bottom are the areas that will take the most punishment from water. A good coat of paint will help protect those areas.

Of course, make sure the structural post is in good shape...including the base...before you start with the decorator post.

Good luck.

Have a nice week...

Trent

Cat...the OTHER white meat!

[Silvan]

Yeah, gack! MDF porch columns? I think I'd be afraid to see what the rest of that house is made from. Probably popsicle sticks and papier maché with some duct tape and bubble gum hidden behind the drywall.

This tale brings to mind a buddy of mine who made a living for some time fixing porches in some big subdivision where the developer used plain, un-treated pine to build all the porch railings on every one of the cookie cutter houses in the neighborhood.

Anyway, I agree with you two completely. Solid wood. Rot resistant. No MDF under any circumstances.

My own porch columns are going to need replacing soonish, and they're structural. I plan to use all PT, and maybe even face out the bottoms with some kind of machined plastic, if I could find thick blocks of melamine or something and rout a profile. Wood to standing water contact is a bitch, and under those circumstances, PT just takes longer to turn into termite fodder.

[Leon]

Correct and the inside of the house wall is not the problem here. The inside of the columns that normally sit on a surface that is very often exposed to standing water is what we are talking about. Further more, if you took the precautions with the columns as the walls in a house, you would also seldom have a rot problem. Exterior walls however are elevated above grade and do not stand in water. Modern day homes, at least those built in the last 40 years use a water barrier to help keep water from coming contact with the studs.

[Trent©]

Standing water will not hurt the inside of a column that is painted and caulked...i.e., maintained.

My last post of this subject.

Have a nice week...

Trent

Proud member of the Roy Rogers fan club!

[Leon]

Good.

[Trent©]

Do you believe EVERYTHING you read?! lol

Have a nice week...

Trent

Proud member of the Roy Rogers fan club!