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I’m laying a porch floor next week that’s Phillipine mahogony boards, 1.25 inches thick, t & g, random widths (5, 6, 7 inches actual). They were milled dowm from 8/4 KD lumber. I’m just wondering if I should try and gap them out a bit when I lay it down, on the assumption that they will grow in width substantially come summer. They’ll be pre-painted on all 6 sides with polyurethane porch and deck paint.
I’ve never gapped any flooring out when I’ve laid it indoors, and have actually had problems a couple of times with later swelling at the joints when I’ve laid floors in the skinny season.I would think it would be even more problematic laying Kiln-dried flooring for an outdoor floor in winter.
Steve
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uh, steve... good luck.. i bet the answer is going to involve a good moisture meter reading of present condition..
outside... hoooo boy.. damned if you do and damned if you don't...too tight and it might buckle.. too loose and gap-city... wide boards..
get the reading... get it to equilibrium and seal the hell out of it
one of the flooring pros might have been up against this one
*Steve, I will repeat what Mike said about laying the boards as dry as possible. I have not used mahagony that wide, but the 3-4" stock I worked with on boats I found to be pretty stable. I have used 4/ 4 x 6 and 8" redwood for a porch. That was dry ( about 7% ) and square edged which I allowed 3/16" spacing. I have detected very little movement and for the most part it has only a top coating of a penetrating oil finish ( Behrs ). And the t & g fir ( 1x4 ) I used on several other porches responded over time with very little movement. Again I used a penetrating oil finish. Also the porches all had very good ventilation under the decking.I would suggest a good penetrating oil finish rather than urethane. I think that sealers like urethane prevent the natural moisture equilibrium from occuring. The possible problems of checking or even worse the of splitting the deck boards are there. Another advantage of penetrating oil is that it replaces some of the moisture and helps stabalize the drying/ wetting process thus miytigating some of your movement potential. It is not my business, butI was wondering why would you want to paint the mahogany? Why not finish it bright? Be as it may, I would suggest you use a good oil-based primer first, maybe add some penetral to increase absorbtion before you use the poly paint.just some thoughtswalk gooddavid
*I'm painting this very nice clear mahogany stock because it's for an 1835 Greek Revival Porch restoration. Paint or bare wood are probably the only historically correct options. That is also why it is so wide and so thick.I was planning to use Benjamin Moore's urethane reinforced porch and floor alkyd enamel. I've had good luck with it on porches in the past (though I've not used mahogony before). Moore recommends no primer when used on bare wood. The paint store tells me that is because primers are too soft to use in a floor application.The boards sat in my truck in the rain (covered) overnite, and were moved into the painter's cellar today for painting. That's about all the time I can afford for seasoning, as I have to get this done and move to Minnesota ASAP.I doubt the boards will ever be any drier than they are now. My main worry is buckling. I was thinking of maybe a 1/16" gap. Maybe more?Steve
*steve... i assume the boards lay from the house out... and the joists are parallel to the house.... i would lay them firm.. but no concious gap..i just wouldn't force them as if it were strip oak interior..from your description, i'd guess the bigger threat is buckeling...say the run is 40'.. can you start at the center of the front door and center a 10' section on the door then leave a 1/8 gap and lay the next 10' section.. etc...use just enough force to straighten the run out...another thing i had luck with on painted floors on porches..exactly what you are doing... painting everything..are you moving to Minnesota for relocation or a new job ?
*Steve, Mahagony is a fairly stable wood. My big concern is maybe they are not all that dry and you may experience more shrinkage than swelling. You do not say where you are but with rain at night and 1835 Greek Revival, I am guessing maybe Virginia or Maryland. Anyways, Mike's idea is a good one; lay them just snug, but not tight. And I would consider facenail , though if your widest board is only 7" ( a true 7" on the face ? ) then you are probably fine blind-nailing. I am assuming also that you will work a pattern say 5-7-6-5-7-6, which will help mitigate the swelling and shrinkage problem more than if you ran them say 7-7-6-6-5-5.I like Benjamin Moore products and bow to their reccomendations. I am not a big advocate of painting wood and never have used the product you have chosen. Just in general, I find if I keep the wood oiled well with my finish, I have less problems with wood stability due to moisture. The thought on the primer was not so much for surface hardness, but for wood penetration, sealing and bonding of the paint. Apparently the paint you choose is self-priming.good luck to you on this project and on your upcoming movewalk gooddavid
*Mike and Dave,Thanks for your thoughts. This is cental New York. Rain in January. Was darn near 50 degrees two days ago! It's a wacky winter this year. I don't think we've been below 0 once this winter when normally it would have hit -20 once or twice by now.Yes Mike, you hit it just about on the head. 36 foot porch, 6 feet deep, joists parallel to house. With a long run like that buckling was my main concern. I like the idea of a small gap every ten feet or so. Walking the dog this morning I was thinking about face-nailing or even face-screwing and filling since it's paint grade anyway.Moving to Mpls for a variety of reasons. The economy here stinks...even in boom times. I'm from there originally and my family is out there. My wife is getting her MBA at the University of Minnesota right now, and I would rather live with her than without her. I've lined up a nice job doing primarily design work for a small (3 office, 5 field) remodeling company.Mike, you'll appreciate this...I have to switch from Vectorworks to Chief Architect because that's what they are set up on. I took a copy of version 7 home with me fom the interview so I could get up to speed on it before I get out there. I'll post about some of my observations on the differences once I get into it.Thanks again for the suggestions.Steve
*steve... good luck in Minn... bet you'll miss Vectorworks.. but wait until you see Vs. 8 of Chief....i got a tiny peak at a beta.. 8 should be out SOON.. apparently the usual last minute bugsMpls has plenty of old lady Vic's just crying for your attention
*I usually thin the first coat with thinner on self priming eurethane paint and have had good luck with the sherwin williams porch and deck polyeurethane paint.
*Steve, I have heard of nothing but problems painting mahogany. You had better check a few sources before deciding on a product. I wish I could give you a recommendation but I haven't run into that yet.
*Paint is on. Boards start going down tomorrow. I'll report back in a year or so ;-)Steve
*Our floor finisher recommends that we put in a gap about a quarter's thickness every 4 ft. when we lay large hardwood floors in an unheated space. These gaps have closed up in the past and we haven't had any customer complaints but I don't know if this makes a difference or just makes us feel better. It does make it appear that you actually know something about the job you are doing. That's worth it alone.
*The floor is laid. I wound up putting a penny's space every couple of feet. It looks like random looseness in the way the boards fit. I think it'll be just the right amount for expansion this summer. Nonetheless, I woke up at three in the morning fretting about wheteher it was too much or too little space, whether the 16d galvanized finish nails were enough to hold it...etc. I hate that these kind of stupid decisions haunt me sometimes. I still worry about a beam I put in a house eight years ago...Steve
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I'm laying a porch floor next week that's Phillipine mahogony boards, 1.25 inches thick, t & g, random widths (5, 6, 7 inches actual). They were milled dowm from 8/4 KD lumber. I'm just wondering if I should try and gap them out a bit when I lay it down, on the assumption that they will grow in width substantially come summer. They'll be pre-painted on all 6 sides with polyurethane porch and deck paint.
I've never gapped any flooring out when I've laid it indoors, and have actually had problems a couple of times with later swelling at the joints when I've laid floors in the skinny season.I would think it would be even more problematic laying Kiln-dried flooring for an outdoor floor in winter.
Steve