I am building a house in Alabama (with painted lap siding)that has an L shaped porch. It runs across the entire front and all the way down one side and will sit approx 3ft off the ground on average. We plan to bring the roof out over the porch with plenty of overhang and also plan to have a solid banister wall. THis should keep the porch floor dry from the top side. Also plan to use mesh and gravel underneath the porch to help with moisture from the bottom. I am definitely going with a wood or wood look floor.
Ques 1 – Should I vent the area underneath the porch to help keep it dry ?
Ques 2 – I prefer not to have gaps in the flooring (but if I have to I can live with it). Would much rather have a hardwood floor look (painted is fine). What should I use ?
Ques 3 – Do I lay the flooring directly on top of the joists or lay a plywood subfloor first?
Thanks for your input. Post some pics if you have any.
Replies
Definitely vent undedr and do not use plywood subflooring. You will get more moisture there than you expect.
You should frame this so that the surface decking runs perpendicular to the house, with a pitch away of about 1/8" per foot to facilitate drainage. Do the kneewall suspended so that water can drain out.
For material, heart opine or clear verticle grain fir T&G were typical, especially in the south, but good heart pine is nearly unavailable and gettting very expensive for a porch, whiole the quality of the fir available is going downhill.
You should see if Ipe` is available in T&G in your area, or consider a manmade composite called Tendura. This latter is my primary recommendation for this porch.
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I am currently researching IPE, Tendura, and Choice Dek after reading the archives on this site, but why is drainage an issue if the entire porch is covered ? Also what is the difference in the moisture factor when using plywood if the boards I end up using are not installed with space in between ? By the way, I am not arguing the issue for or against, just trying to learn, so please, elaborate further my brother...share more of your expertice !!
Jcrew2
"...why is drainage an issue if the entire porch is covered ?"
I'm not a builder, but to my common homeowner's mind is seems that unless you have it fully enclosed (read sunroom, not porch) then drainage will always be an issue because of windblown rain. When the remnants of a hurricane blow through your town you will have a swimming pool instead of a porch if you don't provide a place for water to go.
first of all let me say, you're correct about it needing drainage away from the house. Believe it or not, I did know that. I guess I should rephrase my question. As long as there was adequate slope away from the house, couldn't I run the boards parallel to the house ? For example, the porch runs from left to right across the entire front of the house, and from front to back along the entire left side house. I think that the front section would look good running perpindicular to the house and the slope away from the house takes care of drainage. But I think the side section would look good running parallel to the house because it is the longer axis of the house. I assumed that if I sloped the porch from front to back that the water could run in that direction and drain off on the back side of the house.
A minimal pitch of 1/8" would drop your porch five inches in forty feet. if you can handle that appearance, you could probably do it your way. But if you try to drain water across the joints in a T&G, you will triple the amt of water trapped in the joints, encouraging rot. Same with polywood under it. The water that gets in will have barely started to dry by the time you have the next wind blow more water in to wet things again. It is a simple fact of nature. Anywhere that you put two pieces of wood in tight contact on an exterior, it will get wet, stay wet, and rot soon.Let me give you an example.
There is a summer house here on the island that is owned by a widow who is trying to sell it. I got a call to go down and replace a rotting front step. I am so busy that I was driving down in a mind to tell her that I could not do it because I was assumiong from past experience, that once I touched one rotted board, all the rest of the set of steps would show there age. I was paying her a courtesy call, because she is a nice lady, but time is short nowadays...But when I got there, I saw that these steps had beeen rebuilt sometime in the last ten years. The three other treads were fine - solid clear fir 5/4 x 12 ten feet long, painted.
The rotted one had a different condition though it was the same material and paint. She had had three pottery barrels with plants growing in them for decoration last year. They stayed rioght there all winter. ine only one year os this sort of misuse, theyhad totally destroyed an otherwise good piece of lumber, because they kept it wet.
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I think that the front section would look good running perpindicular to the house and the slope away from the house takes care of drainage. But I think the side section would look good running parallel to the house because it is the longer axis of the house.
If you're talking about the deck boards, I'm confused as to why you'd do it this way. Simply stated you'll get a better job if you bolt ledgers to your house's rim joists, then run all the deck joists out to a supporting beam. The joists will then be perpendicular to the house all around, and your deck boards will be parallel to the house on both sides of the L. In other words, frame it like a very low-slope hip roof, obviously pitched away from the house all around.
Dinosaur
A day may come when the courage of men fails,when we forsake our friends and break all bonds of fellowship...
But it is not this day.
I am planning on using 5/4" IPE TG for our front porch. The problem is that our porch is 8'7" in depth and the boards are sold in 8,10,12 ft...etc. in length. Rather than having to buy 10 feet boards and cut them off, I thought that perhaps I could run a wide board around the wall side of the porch (i.e., parallel to the house) and just butt the 8' boards perpendicular to that. Thoughts, anyone?
bad idea
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When you say 8'7" in depth I assume you are talking about the distance from the front of the porch to the house wall.
But that's unimportant. Again, I reiterate, run the boards laterally, parallel with the house. So the dimension that matters to you is how wide is the porch? Anyway, running laterally you normally buy your wood in random lengths, 8, 10, 12, 14, and 16's. (If your joists are on 16" centers, skip the 10s and 14s.) The longer the average board in your order, the fewer butt joints you'll have. You should have very little waste if your joists are where they're supposed to be.
One mistake a lot of DIYers (and even some contractors) make in laying decks is forgetting to check for the heart in slab-sawn lumber. (If you're fortunate enough to be able to afford CVG lumber, this doesn't affect you.) When wood dries, it shrinks towards the heart, because the fibres run parallel to each other down the growth rings. When the fibres lose their cellular moisture, they become thinner, and slab-sawn boards will cup towards the heart. So it's important to lay deck boards with the heart down. That way, the top surface of each board becomes convex and will shed any water that falls on it. If you lay the heart up, the top surface of the board will become a trough, and water will sit in it.
I normally space deck boards with a 20d nail if green, or with the flat of a carpenter's pencil if KD. This allows good air circulation and drainage.
If you are using T&G deck boards, there is the argument that water will run off into the joints and promote rot unless you pitch the deck along the run of the lumber, which is most logically done by setting the joists parallel to the house and the boards perpendicular to it. But this theory, IMHO, is picking at nits. The top of each board being convex anyway, water will run sideways off the crown into the T&G joints before starting to run downslope off the ends.
In other words, don't use T&G decking unless there will be no or very very little weather exposure. And, all that being said, there's no real reason not to lay out your deck to run parallel to the house. Besides everything else, it looks a lot better and there's a lot less cutting.
Dinosaur
A day may come when the courage of men fails,when we forsake our friends and break all bonds of fellowship...
But it is not this day.
T&G Ipe would make a wonderful floor that would last and last. I did my screen porch last year with it and am thrilled. I got mine from http://www.eastteak.com. Talk to George. They import the cut trees and mill them. There wasn't one bad board in the lot I got. Many deck contractors that lay down a lot of Ipe use that source. Mine was shipped from South Carolina and arrived in Virginia in only four days. They also have a mill on the West Coast. If you want to read much more, go to the following web site for a wealth of information on decks and porches:
http://www.homeressources.com/forum/list.php?f=7
East teak looks like a fine company, but I got a bit of confusion about them milling the ipe`. i had read not long aago, that the countries where Ipe` is harvested are now controlling it and requiring that the milling of the product be done in country and not in USA so they are providing jobs locally for the native populations. So, I reason, either ET is not milling that particular product them selves or they are getting around this by importing large sized timbers of the stock and milling down from there once it gets to this country, or maybe there is a country or two who do allow the export of the raw logs and the article I read was a generalization. Overall, It doesn't seem to make sense to do it with labor cost what they are in th eUSA when the originating country would rather do it for you
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I was told by East Teak that they import Ipe logs in container loads and do all the milling in the USA. It may be that the orginating countries in South America do not have mills set up to do the milling. In any event, East Teak prices were very good, much less than local lumber yards, service was outstanding and milled lumber quality was first rate.
What kind of price, if you don't mind sharing. I pay $1.15/LF for 1x4 square edge
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My experience is a little dated as I bought Ipe in February 2004. But I paid:
5/4 x 4 tongue and groove, fnished to 15/16"x3" face = $1.25/lf
5/4 x 4, S4S, E4E, finished to 1"x3.5" = $1.05/lf
5/4 x 6, S4S, E4E, finished to 1"x5.5" = $1.55/lf
2x4, S4s, E4E, finished to 1.5"x3.5" = $1.61/lf
Freight was $0.181/lf
George at East Teak could give you an updated price. I have read that Ipe is in tighter supply now so George is suggesting Cumaru as an alternative, a close cousin of Ipe and a better value now.
Don't know about tighter. I'm still paying same price for past three years - an amazing thing given the instability of lumber prices in general over that time span.
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I know nothing about choice dek
Never used it
Ipe is excellent. I use it for most of my decks.
But for the design you describne, one that is very traditional for your locale and climate, the Tendura was developed specificaly to look just like the old Fir decking that was traditionally so used and then painted. tendura cannot be used out in the open, but is ideal undedr a porch roof, and your own body will bne rotted before the Tendura is.
when you use Ipe`, it is best to have it square edged and allow a tiny gap for drainage. I discussed this with a wood scientist at the lumber broker that supplies me. He said that he doubted that ipe would have a problem rot-wise with T&G edging, but that the general ruyle was not to use any T&G when it is exposed to weather, which in spite of your assumptions, will definitely happen. The problem being that when water gets into the T&G joint, it will add to rot concerns. Even though Ipe` is near rot proof, there are other problems that can comabout as a result of trapping water in such a joint
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SORRY FOR THE LENGTH OF THIS RESPONSE! I've read the full discussion here to date, and have some suggestions. Having done maintenance painting/finishing on many homes (new and up to 120-years old, northern Midwest, not South) with a porch treatment similar to what you describe, I can report the following:
(1) If you are installing decking, i.e., rounded-edge boards with drip space between the boards, I have no information for you -- I've never seen this approach on fully-covered and partially-enclosed space as you describe.
(2) I have worked on several porches constructed as you described (both old and new), which were either painted or varnished, tongue & groove flooring of a wood not known to me -- probably northern white cedar or old growth Michigan pine. If finished properly, these floors provide a wonderful surface for living -- easily mopped clean, nice smooth surface left as is or decorated with area rugs. Owners often paint these in a light grey floor enamel, or dress them up with an accent color. Stunning if done well. I worked for a very high-end builder who did several homes with this type porch. Gracious living, but a challenging construction situation.
Your original message indicated you preferred a smooth painted or clear-coated floor, not decking. If that is what you're aiming at, I have several comments:
Water exposure -- The situation you describe does not get regular rain, but I think other readers are correct -- rain will blow in, so the floor must be able to get soaked from the top periodically. For this reason you absolutely need drainage -- 1/8" or 1/4" per foot. I know 1/4" per foot seems extreme, but it is common in my area.
Also, the flooring should be installed perpendicular to the building, so that any water which does blow in runs down the boards and flows with the grain and with the joints. In my experience, wood does not remain perfectly stable over time, especially outside where humidity and temperature changes are more dramatic. Boards will cup and bow slightly over time, and some of the T&G joints will become raised. If the boards are installed parallel to the side walls, water running off will get backed up by the slight variations in the surface of the wood, and it will sit in little puddles. Then it will have more opportunity to soak down into the wood under the paint -- through a T&G joint which opens up after the wood shrinks, through a scratch in the paint left by porch furniture -- you get the picture.
Make certain the floor decking is good and dry before installation so shrinkage is minimal -- you already know that.
At any steps, install a nosing parallel to the steps in the flooring, like you would for an interior hardwood floor that ran perpendicular to a top step.
I do not necessarily agree that the exterior wall needs to be raised to allow drainage -- how large is the overhang beyond the porch? -- but I have worked on homes where the builder constructed "scuppers" in the exterior wall every 10 or 15 feet to allow water to flow out -- like on a boat, to allow the deck to drain.
Regarding painting or clear-coating, I have definite advice:
(1) Polyurethane or prime the bottom of the flooring before it is installed. Paint will yield a more durable surface, but a polyurethaned or varnished floor in this application can look stunning. Use a good long-drying alkyd primer, if painting. Prime all ends well before installing. If clear-coating, seal the ends well.
(2) If painting, use a top quality exterior porch paint. 2 coats minimum. This is one situation where I would use alkyd paint exterior. Semigloss or gloss.
(3) Where the wall meets the floor, I recommend a thin, high-quality siliconized latex caulk bead, fingered in, and let it fully dry and shrink before painting.
Please note I am not a builder. I'm just a painter. But as I said, having done LOTS of maintenance painting on old and new structures with porches as you described, I've seen a lot of rot, a lot of failing surfaces, and I've become sensitive to what type of carpentry works.