View Full Version : Deck question
Dave M
10-02-2007, 03:09 PM
I'm changing my deck on my camp from a 5' square landing with stairs to a 5'X21' deck along the house with a ramp to the driveway. I live on a hill and I have to walk down a hill and then up the stairs. This is getting old. I plan using pressure treated lumber with 3 boxed frames along the camp and 3 boxed frames out to the driveway. Each frame will be 7'X5'. My question is can I use 2X6's for a 7' span. This is what I'm using now on the existing frame. The joists will be the long length in the frame.
Any other suggestions will be helpful.
Thanks
Dave M
LIforrelaxin
10-02-2007, 07:20 PM
I would think you would want to use a 2X8 to span seven feet. A 2X6 might cut it (after all I used 2 X 6 on my dock which has 9 foot section... But I was also concerned with wieght.... A deck being a permanent structure I would go for the extra beef..... ALso I would suggest not building the structure in sections I would constuct the deck as a whole unit.
Another tip.... I have used 2 X 4 in the past for my decking (both decks at the camp use this technique) it saved a little bit of money over using the traditional 6" decking boards...
now knowing that I am not a professional, a tip if you concerned about building the structure strong enough would be to talk to people at either Lowes or Home Depot... A few years pack a friend went to the Depot with his idea, span distance etc. in hand.... and they recomended what size lumber to use and even made a blue print and calculated what he needed....
Last you may want to contact the local building inspector... you may find that the town, city, or state has specific guidelines that specify what the minimum lumber size is to be over specific spans.....
Formula260SS
10-02-2007, 07:23 PM
I believe a 2x6 can span 9', the rule of thumb is 1.5 times the height of the board.
6 x 1.5 = 9
Another option is 12" centers rather than 16", my deck is on 12" centers and solid as a rock with 5/4 decking.
"...I live on a hill and I have to walk down a hill and then up the stairs. This is getting old. I plan using pressure treated lumber with 3 boxed frames along the camp and 3 boxed frames out to the driveway. My question is can I use 2X6's for a 7' span...Any other suggestions will be helpful..."
It does get old. We did the same changeover 15 years ago.
The contractor we hired used 2x8's, which is what I have used everywhere since, as the strength-to-cost difference isn't that much. I use 2x8's for planking as well. They keep their strength better through weather damage and time, and their cost is (or was) only a little more than 5/4ths.
You didn't mention "Trex" planking, whose only negative feature is relative strength, and would require more support (than 5/4ths or 2x8's would) for planking.
Speaking of support, I've managed to use existing Sonotube locations (which haven't sunk appreciably), and would like to hear of any alternatives being used at ground level.
Suggestions:
1) Inspect your sill. This is a better time to put in a PT replacement than after installing the walkway.
2) If you attach the frames to the house sill, use flashing.
3) Pressure treated lumber is wet and heavy when first bought. Have it delivered now for building in the spring and space each board in storage to keep them straight.
4) Depending on the trees nearby, spacing on the planking can be important for self-cleaning. If the underneath is not accessible, small trees can find the sun through the spaces and become a maintenance item. However, on a long run like yours, you can save a few bucks with wider spacing.
5) I'd modify the existing staircase (rotate it 90° away from the house) so you gain access to the ground in the middle of the walkway, and save even more "steep" steps by not having to go around the walkway ends.
6) Check each board for curvature ("crown" in the trade), and put the "crown" side upwards.
7) Your insurance carrier may specify a handrail arrangement—one different than the design you have planned. (Though my carrier was happy with my design).
My personal favorite construction technique—though it's very expense—is to use ¼" x 4" stainless steel lag bolts on 2x outdoor construction. Changing out the occasional weak plank, tightening for wood shrinkage, and changes in design are more easily made. In bulk, they can be bought for less than $1 each from a few vendors.
Drop 2 from the nominal width of the lumber, then double it for the acceptable span on 16" centers:
2x6: (6-2) x 2 = 8
2x8: (8-2) x 2 = 12
2x10: (10-2) x 2 = 16
you can also google "span tables" and get other acceptable solutions with other "on center" layouts
SIKSUKR
10-03-2007, 01:25 PM
Very good recomendations from APS.His point about wet PT is correct but I have had some bigtime warping occur after long drying periods.FWIW,I like to install any demensional lumber in a short time (within a month) after taking delivery.
Rattlesnake Guy
10-03-2007, 05:14 PM
Anybody know how long the kinder and gentler pressure treated lumber is going to last in the ground, in the weather or in the water?
idigtractors
10-03-2007, 05:40 PM
One thing one must remember when using any type of PT for decking is that it checks terribly as it dries out and the splinters are horrible especially on kids bare feet. You can not sand or do anything to correct the problem. When we install decks we tell the customer and show pictures of past jobs and give them references from the customers regarding same. We push very strongly for the Trex or other comparable materials for decking. One can use the standard 16" o/c when using these materials. Yes cost is more, but just one bad splinter in a child's foot is well worth it. This also goes for the pets paws. :)
LIforrelaxin
10-04-2007, 02:07 PM
Anybody know how long the kinder and gentler pressure treated lumber is going to last in the ground, in the weather or in the water?
That is anyones guess at this point. I have heard that it is supposed to be just as effective as the old method. However I have my doubts... if I remember this thread though I will post my finding in a few years as I just barried one side of a PT board that retains some sand by one of my walkways......
idigtractors
10-04-2007, 04:13 PM
That is anyones guess at this point. I have heard that it is supposed to be just as effective as the old method. However I have my doubts... if I remember this thread though I will post my finding in a few years as I just barried one side of a PT board that retains some sand by one of my walkways......
Remember the old type of PT is for ground contact only. That does not include burying per my salesperson of the material. The new type which is now being sold and I can not remember off hand the proper name for it does not have the arsenic, but another chemical. One needs to use the proper nails and hangers etc with it or they corrode.
The arsenic has been replaced with copper in the new pressure treat. All the new pressure treat timbers are guaranteed for 40 years. (8x8, 6x6,4x4,4x6 etc) They are treated to a .40 retention and you can put it in the ground and it will last 40 years. All 2" dimension-2x4-2x12 is treated to a .25 retention and it will last 40 years with an above ground application only. All decking is teated to .15 retention and will last 40 years above ground with maintenance-putting a water repellent on it once a year. There is a newer pt in California more environmentally friendly, with the same warranty but only if used above ground. It is borax treated.
I personally would only use the composite deckings for my decks as someone said, it never needs to be treated and doesn't have splinters
Remember the old type of PT is for ground contact only. That does not include burying per my salesperson of the material. The new type which is now being sold and I can not remember off hand the proper name for it does not have the arsenic, but another chemical. One needs to use the proper nails and hangers etc with it or they corrode.
Burying PT 4x4s was a bad idea before 1992's Hurricane Andrew hit new construction in Florida. Long lengths of entire PT fences went airborne, striking other structures—even knocking reinforced concrete sills off neighbors' houses.
The usual practice of contractors was to pour concrete around the buried posts; unfortunately, the wind broke off the posts at their most weakened point—at ground level—and fence sections were carried elsewhere with the wind. (Although even chain-link fences were affected, as debris would pile onto them and they got driven—posts and all—flat to the ground.)
In short, I'd say "burying" depends on the stresses you expect to put on the PT-wood—or what one could expect under the worst scenario.
Near water, PT seems to stand up pretty well. Our dock is over 25 years old, and the PT parts are holding up just fine. For some reason, contractors didn't use PT on the most important structural parts. :confused: Rotted timbers would break after Ice-Out, when lakeside contractors were busied with winter's bigge$t dock problems, so I'd have to replace the rotted pieces myself. :rolleye2:
Waterproofing treatments are a really good idea, but it doesn't do much good when Spring's over-full lake level covers the dock! :rolleye1: :emb:
Dave M
10-10-2007, 03:21 PM
All, thanks for all your inputs, they are helpful. I planned on using PT for the frame with 2X's for the decking. I've tried the 5/4 boards and found it spongy even on 16" centers. If fact my previous deck frame is made from non-PT. What my father in-law taught me was to use roofing paper on all the joists. No problems at all even after 15 years. I plan on using lag bolts to the house. I have texture "111" for my siding so flashing will be an issue. Wonder if I should cut the "111" so it sits above the deck and put flashing under. Don''t really want to do that since down the road I'll put a foundation and move my door entrance. Any suggestions.
Can I assume I will still need a building permit even though I have an existing deck, although shorter. I'm sure they'll have all kinds of rules for this.
Thanks
Dave M
LIforrelaxin
10-10-2007, 11:39 PM
Humm T-111 does bring up some flashing concerns.... never thought much about that....How much of a roof overhang do you have? Although not the best solution if you have a good overhang or gutters so that most of the water will not be running down the side of the house you might be able to call that good enough.... because all I can think of with T-111 would be to cut it and make seem where you want to start the flashing....
As for a permit, my quess would be that yes you will especially if you have nosey neighbors....Your enlarging the structure and adding value, the town is going to want to know....What the town will require for documentation and possible inspections will differ from town to town..... One thing I will say however is that they will probably not permit your Boxed section idea....I would just call your local town hall and talk with the building inspector and they will let you know.... I know they where very good in Moultonborough when we fixed up our camp.... and even gave my Dad advice and told us on a couple of our projects that permits where not neccessary.... the only thing they didn't like was when we moved our electical service panel oursleves but we did everything to code and the inspector signed off on it no problem....
"...Wonder if I should cut the "111" so it sits above the deck and put flashing under. Don''t really want to do that since down the road I'll put a foundation and move my door entrance. Any suggestions..."
I don't see how you can avoid rainfall on the walkways—and it is that splashy runoff that can keep the sill wet and cause mischief (carpenter ants, wood rot). Maybe trim off the T-111 and store the pieces? When the new foundation goes in, the siding can be restored where needed.
Another suggestion is to keep all the stair-steps exactly the same measurements. A mix of stair heights and lengths can be tricky to negotiate—especially at night. If I had it to do all over again, I'd also design each "level" so that it takes the same number of steps to the next level throughout the property—if possible.
Regarding the railing: Those thin galvanized metal brackets will speed construction and are popular enough. Their downside is that they're not very strong, gradually weaken with use, and can't be tightened. I'd use bolts to secure 4x4 uprights—notching them to fit if desired.
SIKSUKR
10-11-2007, 10:12 AM
APS,good advice on the tread rise spacing,but not only is it "tricky" to negotiate,it is not code.All stairs must have the same rise for the reason you stated.
As to Davem,I assumed you put roofing paper on the joists so they would not squeak?I don't know of another reason.I would definately cut your t-111 back for flashing.T-111 has been around for a long time and probably won't be a problem getting it when your ready to change.
idigtractors
10-11-2007, 11:52 AM
As to Davem,I assumed you put roofing paper on the joists so they would not squeak?I don't know of another reason.
In the old, old days, we were taught that laying the roofing (tar paper) 4" strips on top of the floor joists helped them from getting wet and have sitting water on them therefore stopping them from rotting. It actually worked. If you have seen any location that had this done you will see that the rot was not present or barely present on those particular joists. :)
Rattlesnake Guy
10-11-2007, 02:10 PM
I have had two previous houses where rain falling from the roof bounced off the deck and splashed up under the clap boards well above the flashing. This caused rotting to the extent that the walls had to be replaced.
Several years ago I saw a neighbors house where they had installed grating in place of a row or two of deck boards to allow the rain falling from the roof to largely pass through the deck without splashing. I have used the technique on a deck I built and it makes a big difference on how much water splashes up. The aluminum grating is the same thickness as the Trex.
SIKSUKR
10-12-2007, 11:35 AM
Thanks IDIG,that does make sense.Good idea on the metal grating RG.I have used that in front of entrances which works great for kicking snow and dirt off before it gets tracked in the house.
WINNOCTURN
10-12-2007, 03:27 PM
I have had two previous houses where rain falling from the roof bounced off the deck and splashed up under the clap boards well above the flashing. This caused rotting to the extent that the walls had to be replaced.
Several years ago I saw a neighbors house where they had installed grating in place of a row or two of deck boards to allow the rain falling from the roof to largely pass through the deck without splashing. I have used the technique on a deck I built and it makes a big difference on how much water splashes up. The aluminum grating is the same thickness as the Trex.
Rattlesnake Guy,
I have the same problem. Where did you get the grating?
Thanks,
WINNOCTURN
camp guy
10-13-2007, 09:01 AM
I just read through this post and I can only offer up one idea: If the distances and elevation changes don't work out so you can have steps required by Code, maybe you might want to think about having ramps, with landings between them. This way you can meet the Code for the step construction, and between you can have a gentle grade ramp. I did this and it worked like a charm.
Rattlesnake Guy
10-14-2007, 09:19 PM
Rattlesnake Guy,
I have the same problem. Where did you get the grating?
Thanks,
WINNOCTURN
McMaster Carr is the source I used. I used the aluminum to avoid the corrosion.
Link to catalog page (http://www.mcmaster.com/ctlg/DisplCtlgPage.aspx?ReqTyp=CATALOG&CtlgPgNbr=2019&RelatedCtlgPgs=2019,2020&term=Bar%2bGrating&sesnextrep=362724980680961&ScreenWidth=1920&McMMainWidth=1696)
SIKSUKR
10-15-2007, 01:12 PM
McMaster is my bible.It's sitting right here next to the computer.I order from it at least once a week.Anything you could want to build/repair machinery and the like.Catalog 111 right now,am I due for a new one?
WINNOCTURN
10-15-2007, 02:28 PM
McMaster Carr is the source I used. I used the aluminum to avoid the corrosion.
Link to catalog page (http://www.mcmaster.com/ctlg/DisplCtlgPage.aspx?ReqTyp=CATALOG&CtlgPgNbr=2019&RelatedCtlgPgs=2019,2020&term=Bar%2bGrating&sesnextrep=362724980680961&ScreenWidth=1920&McMMainWidth=1696)
Rattlesnake Guy,
thanks.
siksukr,
the book is to heavey. i go right to their website. their shipping is fantastic. on most items, if it is in stock i will have it the next day.
winnocturn
islandAl
10-15-2007, 04:20 PM
RG
The bearing bars look to be running in the same direction as the stringers would be. So what have you done to support the setup?
Did you use the smooth version and does it get slick in the winter?
Thanks for the idea.
Rattlesnake Guy
10-15-2007, 07:07 PM
In my project I ran the joist at a 45 degree angle with 12 inch spacing on the joist. (For reasons related to the rest of the project and not by the grating). I bought 1" aluminum 2 foot x 4 foot panels. The bars that hold the ribs together are easy to trim into the desired width. The strong direction ran parallel to the house. On a conventional joist scheme, you can simply do the same thing. The main thing is to make sure the ends are supported so no one takes a trip. Fortunately, the 4 foot panels make this easy.
McMaster Carr is absolutely amazing. I would love to see the wharhouse that allows them to do what they do.
It took me many years but I am now an online version junkie. I don't even own a catalog anymore. So much easier to find things.
islandAl
10-16-2007, 08:25 AM
I had been misreading the catalog. :confused: Make sense now. :emb:
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