DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Building & Construction (http://www.diychatroom.com/f19/)
-   -   Newbie needs to build a deck addition (http://www.diychatroom.com/f19/newbie-needs-build-deck-addition-103743/)

toolbot 05-06-2011 10:12 AM

Newbie needs to build a deck addition
 
So I would like to add a small addition to my deck, connecting the main deck to the pool. Here is a picture of what I want to do, the yellow section is what I need to build:

http://dl.dropbox.com/u/231214/deck.jpg

I have never built a deck before but did watch (and took many pictures) the company that installed our main deck. I have some books, and am pretty handy with tools and have basic woodworking skills.

The main question is, where do I place the supports? I asked Lowes to draw this up with their deck design software, so they could give me the print out of all the materials I need, and the location of the supports, but their system can't handle this design.

I would definitely appreciate any tips/suggestions you might have. I plan on following the construction methods used by the original builder. Thanks!

Willie T 05-06-2011 10:18 AM

Buy one of those Deck Building books Lowe's and HD sell. They're really pretty good.

toolbot 05-06-2011 10:19 AM

Yep, I bought one of those as well, and contains a lot of good information I will be using.

toolbot 05-07-2011 07:34 PM

Really would appreciate advice on post/beam locations. Have gone through several books now, but would like input from people with real experience.

BigD9 05-07-2011 07:57 PM

I did almost the same thing you are wanting to do. I got Lowe's to design it as close to the design I wanted and then I modified it from there to fit exactly what I wanted. That way it gave me the post size and spacing. Then my next door neighbor, who thinks he knows everything about everything, came over and told me I was doing it all wrong. I was way over-building the deck and wasting money. I knew at that point I was doing it properly because I've seen his work!

Don't forget the permits if you need to get then in your area.

Ron6519 05-07-2011 09:40 PM

You have so many direction changes on this structure. Where it meets the old deck I would put a row of supports a few feet away from the old deck and cantilever the new deck into the jogs.
Two supports at the end.
Row of 3 supports midway between the two ends.
Another few along the curve. The number depends on the radius of the curve.
Ron

toolbot 05-08-2011 01:45 PM

I just finished doing a mockup in SketchUp, thinking that I have the foundation covered, but I am definitely confused when it comes to the joists and decking. I'm not sure how I would create joist headers so close to the pool, so I can put down the decking without running into stability issues. Here are a couple of views:

http://www.dropbox.com/gallery/22475563/1/deck?h=b4efc8

I know there a couple if issues, but please take a minute to let me know of any major issues. The books are a little help, but not enough in this scenario. It's a stand alone deck, using 16" off center joists, and 5/4"x6" decking.

I was told 12' is the longest lengths I should order for both the 2x8's and the decking, so that's what I used as the largest lengths.

Thanks!


edit: Didn't see your suggestions until I already finished the drawing.

Ron6519 05-08-2011 01:52 PM

The arc around the pool would be a continuous beam, not a bunch of hurdle like supports. The beam would link the support posts together.
Ron

toolbot 05-08-2011 03:28 PM

That's what I thought as well, but I am having trouble figuring out how to do this, and the book didn't seem to cover this.

dpach 05-08-2011 10:27 PM

3 Attachment(s)
Please make sure to get a copy of the local building codes for your city. Books have very good ideas, and cover the basics, but you must have joist spans, beam size and methods, post spans (depends on type of beam/size of beams you use), joist size (2x10, 2x8 etc), etc that meet your local code. You will also need to find out the max distance between joist braces (braces between the joist for lateral stability) and this can also vary from city to city.

I built my new deck last summer (have to add railings and stain this summer) and found very good advice online by googling. But I found out a lot by speaking with the city's building code/permits office and building inspector. For example, books say to dig footings/piles to below the frost line. My local codes call for minimum 8 feet and strongly recommend 10 feet because I live in very gumbo type clay where frost puts so much side pressure on footings that frost heaving can suck the footings up (and leave a holly below the footing). By going 10 feet I would have 4-5 feet below the frost which would stop this heaving due to side pressure. I went 12 feet.

Another example was local codes called for minimum 4x4 posts, but local inspector recommended 6x6 because as wood dries and ages, it can get vertical cracks up the posts lengthwise. He's often seen 4x4's with cracks on each side that have actually met in the middle of the post, where as 6x6's would rarely ever have this happen. Plus your footings diameter will depend on depth and also post size (wider post requires wider footings).

As already mentioned, make sure you have a permit. It not only covers you and future issues, but it allows you to speak with a permit writer who will give you some very good info.

One other tip for later, I strongly recommend spending the $300 or so to blueskin (or another brand of barrier) the tops of the joists and beams. The most common cause of joist failure is where the deckboards get screwed to the joists -- rain sits under the boards on top of the joist and soak into the screw holes. That is the most common cause of joist rot. This membrane is rubber surfaced with a tar based compound under it that seals around the screws as they go into the joists. Its a pitty to see someone tearing down a deck because the joists fail in 10 yrs.

Good luck!

Ron6519 05-09-2011 07:40 AM

Quote:

Originally Posted by toolbot (Post 644075)
That's what I thought as well, but I am having trouble figuring out how to do this, and the book didn't seem to cover this.

Books don't cover every contingency possible. This would come from experience and sometimes professional guidance.
I would place posts every 4 feet or so. The middle posts would be 6x6's. The ends, 4x4's. Since the beams will hit the posts at various angles, you could notch each post so the beams would have a flat surface to bolt to the post.
I'm sure there are other ways to do it. Others will come along and make suggestions.

Ron

Daniel Holzman 05-09-2011 07:48 AM

Ron, I am assuming that is a typo, you don't mean to place posts every 4 inches? Probably every four feet? Even so, posts every four feet are almost certainly well in excess of code requirements. As previously noted, get the code guide for your area. When I built my deck, the building inspector gave me the "Prescriptive Residential Wood Deck Construction Guide", based on 2006 International Residential code.

This was a very useful guide, included most of what a person would need to build a deck, including post sizing (6 inch minimum in my town), connection details, nailing, screw and bolt requirements, joist sizing and spacing, footer design, staircase requirements, railing details, bracing, and a few other critical details. You have an unusual shape, however the post spacing, joist and beam sizing is primarily a function of the tributary area of deck supported by each joist or beam, and once you know the required load per square foot it is relatively easy to determine the required joist size and beam size, and minimum post spacing. Then you can play around with your software, move the posts etc. to maintain minimums.

Ron6519 05-09-2011 08:34 AM

Quote:

Originally Posted by Daniel Holzman (Post 644388)
Ron, I am assuming that is a typo, you don't mean to place posts every 4 inches? Probably every four feet? Even so, posts every four feet are almost certainly well in excess of code requirements. As previously noted, get the code guide for your area. When I built my deck, the building inspector gave me the "Prescriptive Residential Wood Deck Construction Guide", based on 2006 International Residential code.

This was a very useful guide, included most of what a person would need to build a deck, including post sizing (6 inch minimum in my town), connection details, nailing, screw and bolt requirements, joist sizing and spacing, footer design, staircase requirements, railing details, bracing, and a few other critical details. You have an unusual shape, however the post spacing, joist and beam sizing is primarily a function of the tributary area of deck supported by each joist or beam, and once you know the required load per square foot it is relatively easy to determine the required joist size and beam size, and minimum post spacing. Then you can play around with your software, move the posts etc. to maintain minimums.

I'd put the posts that close because he was going around a curve and it would let him get the decking close to the pool without added framing between the beam and the pool.
Yes, it was 4 feet.
Ron

toolbot 05-09-2011 07:35 PM

Wife tried to pick up a copy of the building code for my town, but the code inspector told her to just have me come in with my plans and he will go over it with me. Of course, it doesn't help he is only there when I am at work, and while I can find the building code for fences etc online, nothing for decks :/

It looks like the type of footings I used in my drawings are outdated, and known to have problems with moisture. dpach's pictures/deck look pretty good. I guess I need to go buy a more recent book and read up. Are there any other resources for this kind of project?

dpach 05-09-2011 08:34 PM

Here's a couple on basic footings:

http://www.deckmagazine.com/pdf/2007/0701/0701pier.pdf

http://www.finehomebuilding.com/PDF/Free/021180044.pdf

Don't know if they'll help you a lot, but some good basic info. www.deckmagazine.com also has various forums that discuss design, structure, etc specifically for decks.


All times are GMT -5. The time now is 06:14 PM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved