Decks, Patios, Porches and Docks - Decks

I have tore down my pool, and I now wish to make an addition to the deck that was by the pool
Here's my problem, A year ago a friend of mine bulid a large deck and it cost him about $1,000. I wish to make my addition which is about 1/3 the size of his. I had plans drawn up by several lumber Companies( no charge) and I got estimates of $1600 to 1800 and one was 2000. The reason for the difference was treated lumber cost, they say????????? My friend built his with treated lumber also, the entire deck.
Question, do I have to use treated lumber?? or can I use regular un=treated lumber and when done soak it with a preservative? :wall:
I would appreciate a knowledgeable answer
Thanks

treated lumber is not any more water proof than untreated lumber. Treated pertains to insect and rot resistance. If you don't mind replacing it I guess you can use what you want as long as there is no requirement that pressure treated lumber be used. I would at least use treated lumber underneath the deck and definitely for the support posts and beams it will be a lot of work to replace when the carpenter ants and termites eat it. Go with the PT lumber

The real cost to you is the price difference between the treated lumber and the untreated. The untreated wood is not free. Maybe there was a hidden charge for drawing up the plans or something. I don't think the price has nearly doubled.

Lumber prices change daily! There are many other reasons for your project to cost more than your friends. Design differences will mean use of different size/length lumber which will also affect the cost. Unlerss you use cedar or redwood [which cost more] I would not consider using lumber other than PT. The composite materials are also more expensive. The money you would save would disappear in no time with the extra maintinence and short lifespan.

In a 1-2 year period 1/2" OSB can range from under $10 to $19 a sheet. A precut 2X4 can be as low as $2.50 and as high as $4.50.

What your friend paid last year has nothing to do with what the price is today. Lumber, OSB, diesel, concrete, steel -- ALL have seen huge price swings over the past year.

Design is another factor. Some people build decks with large girders and joists and very few footings. I build them with lots of footings and smaller joists and girders. Which way is more expensive depends on what day you happen to buy the framing lumber. The price changes pretty much daily.

Well, I learnt something I didn't know before, Treated wood does not prevent rotting...Thanks I was told by the building inspector that in my area, if I didn't want to use concrete to set my 4x4's in, I could dig down 4 feet(frost line) and pour a concrete pat and set my TREATED post on that. Now I find out I shouldn't put any wood in contact with ground or set them in concrete because the moisture will rot them. How about having a 4x4 treated post, apply asphalt tar to the part that goes in the earth and use them that way???? I'm trying to avoid hiring a contractor because I figure they cost more than the wood.. A good one I mean. Just kidding, please no offense meant or intended.

If you already have the hole why wouldn't you fill it with concrete instead of the post. Just make the bottom a little bigger than the rest and fill with concrete in a sona tube maybe.Put in the anchor bolts for the post supports while the cement is still wet and line them up nice and straight.

How high are you planning to build the deck is the big question in determining what material you should use and how to go about securing your posts. Also are you going to attach it to your existing deck or have it free standing. If it is going to be attached to your existing deck you should try to support it the same way so as to minimize any shifting or settling between them. As far as PT or standard Lumber is greatly determined by the hight off the ground you plan to build your deck. Any lumber 12" or less is recomended to be PT. A way to preserve your PT lumber exposed to the ground is by staining it prior to installation. As far as putting tar on it, it is strongly unadvised as the tar may keep out moisture, it will also keep in any moisture that might or may been be in the lumber and actually increase the rate of decay.

Like Joneq said, if you've got the hole dug, fill the bottom foot or so with concrete, then use a 12" sonotube to fill it the rest of the way up with concrete, backfilling outside of the tube with dirt as you come up. Let the sonotube extend at least 8" above grade, and fill it to the top. Once it's full, set a Simpson CB44 or PB44 in the wet concrete. Give the footings a few days to cure, then attach your posts in the bases and start building the deck.