Why is gloss or semi-gloss paint recommended for exterior house trim?

July 20, 2009 2:37 PM

Why is gloss or semi-gloss paint recommended for exterior house trim?

Hubby and I are in the process of painting the trim on our WW2 brick bungalow dark brown. Before purchasing the paint, we sought the advice of The Google, paint pros, old-timers, and family--everyone recommended a gloss or semi-gloss finish. Being intrepid DIYers but never having painted a house before, we acquiesced. Fast forward two weeks: we stand back after painting two columns & gable porch siding and *hate* the sheen. Shiny (enhanced by the dark pigmentation of the paint and slight surface textures) and attention grabbing--even in partial shade, the gable porch now jumps out in a really unattractive way. We have since walked around the neighborhood and counted just how many houses have similar glimmering trim: not many.

We have 2 questions for the hive mind:

1. Why on Earth is gloss or semi-gloss recommended for exterior trim? Is it easy-to-clean? Longer-lasting? Is bling-bling curb appeal the new thing?

2. Will time, oak tree pollen, and the curing process of exterior latex reduce the shine? Are we screwed if we try to put a coat of flat exterior latex on top of this glossy hot mess?

Just to be clear, we love the color and the paint itself is top notch. It's just the sheen that is making us crazy.

posted by muirne81 to Home & Garden (8 answers total)

I've always heard it's because it's easier to clean. That's certainly been my experience with bathroom and kitchen interior paint (I've never had to deal with exterior, but I'd imagine it's the same reason).
posted by peanut_mcgillicuty at 2:44 PM on July 20, 2009

1) Yes, the smooth finish surface retains less dust and debris, and is easier to clean. Also, the color of the paint remains true over a wider range of sun angles. If you painted with gloss, you might be much happier if you sand a bit, and repaint with semi-gloss. You'll get the same ease of cleaning, with a lot less initial shine.

2) Time, and oxidation will, over time, reduce the shine of glossy exterior enamel, but it might take a year or two. If you're going to repaint, you need to first sand the glossy painted surfaces enough to break the shine, before repainting, for the new paint to adhere properly.
posted by paulsc at 2:47 PM on July 20, 2009

You've pretty much got it. Gloss and semi-gloss are easier to clean and resist scratches better than satin or flat. Flat hides imperfections better, but dark paints can also reveal imperfections moreso than lighter colors.

Liquid deglossers exist, but they're mostly a weak paint remover, and are mostly for prepping a surface to paint over. You could degloss and put flat or satin over the existing.

Have you considered a satin finish? Not quite flat, but not quite semi-gloss.
posted by electroboy at 2:47 PM on July 20, 2009

It's way easier to clean than flat paint. I have a closet that I painted with semi gloss for this exact reason.
posted by reenum at 2:52 PM on July 20, 2009

If you used really glossy plaint, semi-gloss will be a lot less shiny. The sheen will come off a bit as the paint cures, but not that much in the short term.

Note that you will stop noticing it after a while if it makes you feel any better.
posted by GuyZero at 2:52 PM on July 20, 2009

We painted our house trim with a satin finish for just the reason you now dislike yours: gloss is too shiny. It's been four years now and the paint cleans just fine, is not flaking, and we still like it. You may have to insist on the sheen while the paint mixers look at you like you're insane, but you'll be much happier in the end with the satin finish and as long as you're using exterior paint you'll be fine.
posted by cooker girl at 2:54 PM on July 20, 2009

Gloss paint resists the elements better because it's smooth where flat paint is rough. The rough surface gives pollution someplace to hang on and start breaking down the paint. Gloss paint also sheds water better. Similar to how you sand a surface before painting to give the paint a good mechanical adhesion and wax your car to encourage the water to bead up and roll off.

And if your trim does get dirty scrubbing a flat finish can result in a shiny spot.
posted by Mitheral at 7:18 PM on July 20, 2009 [1 favorite]

I've never heard that you should paint exteriors with gloss or semigloss, only kitchens and baths. I hate shiny paint, and it shows every flaw like there is a spotlight on it, so I paint everything in eggshell, inside and out. If eggshell isn't available, I go with satin. I even use the eggshell in my kitchen and bathrooms, despite popular wisdom, and it's held up well (the oldest paint job that we've done is about 14 years old). Buy good quality paint and prep well.

If you don't have a paint sample book handy, for glosses:

flat < eggshell < satin < semigloss < gloss
posted by zinfandel at 7:34 PM on July 20, 2009