rebuilding old deck and it has 2x4 joists, am i crazy?

Question

Most of my elevated deck is rotted, it's 15yrs old. So I have torn it down and am replacing it piece by piece so that it is an exact replica of the previous deck. I'm doing this to avoid 100's in city council fees etc (i replace it, paint it, and no one is the wiser it's 'always been tlike that'). I figured if it was good enough all those years it should be good enough now. I have even used 2x4 joists which is what was there eventhough where i live now it's not compliant BUT my deck is only 5ft wide and 20ft long. The 2x4 joists go into the house and connect to the big house floor joists, they extend out onto a double 2x8 beam that is held up by 4 4x4 posts. The 2x4 joists are spaced about 15inches apart. There is never a load on the deck such as a jacuzzi or many people, I can't see why this would be a problem using the 2x4 treated joists? do you?

Answer 1

As a senior journeyman carpenter , I'll give it to you both ways.

At a span of 5 feet, it is still iffy in the extreme. For an overhang, yes. Where people will have to trust their safety, maybe their life, do you really want to put anyone at risk for for less than 80 dollars?

Yes, Specs have changed. In most cases, those specs change because somewhere, the old ones were found to be inadequate or dangerous.

It was just a couple of years ago that a balconey in Chicago, I think , collapsed under the load from a party...The culprit? Inadequate materials in the joists and attachments, and because there were fatalities, union locals all over the country were alerted for training purposes. The balcony was relatively new, but built out of code.

If you skimp on a wall in a storage shed, it sags. Skimp on an elevated platform designed for people, it is likely to never give a hint of problems right up till it hits the ground.

The 80 dollar figure is MORE than it would cost to use 2x8s per most codes for your span, as opposed to 2x4s, and 2x6 is BARE minimum

Answer 2

Codes codes codes. I've never heard of anyone using a 2x4 as a floor joist, even for a very short run, I don't even use them for studs anymore, the wood is just too full of defects. If one happened to crack it could give way completely; maybe that's the problem. Also, a deck may have to be designed to support a hot tube or what not. Usually codes are designed to be compliant with the worst case scenario. I feel you pain though. I live in the county, not in the city and that's the main reason.

Good luck

Answer 3

If the old deck lasted 15 years I would think replacing it would work, but maybe you can put a 2X6 or 2X8 half way under the 2x4's to help support the load. Then you will only have less than 2.5' span on each 2x4.

Answer 4

I would use at least 2x6 joists 2x4's will sag it doesnt matter where they come from or where they are connected.

Answer 5

Are you comfortable with having your loved ones and yourself on the deck after the project ?
Personally i would replace ever other 2x4 with something larger.
I have done a few of these bootleg jobs myself and all ways tried to make them a little bit better.

Answer 6

sounds OK, just b sure you check load specs for that type of structure.

myself I would cheat and place the top of the 2x4 in to the channel of U-channel metal (alum, steel, reinforced fiber).

that will stiffen the 2x4 and weather seal the upper half of the 2x4s so the chance of rot will be reduced. you will then have to use self drilling deck screws.

inspect and upgrade the house side of the deck for strength.

done this before, works fine. (I am not an architect)

Answer 7

the way you make it sound, the powers that be will never know that you fixed it better than it has to be, so do it right. use at last 2X6's. why take a chance of it failing and getting sued?

Answer 8

i sgest u use the same kind of wood that was their before. make sure its all pressure treated and also paint it with a oil base paint so watr wont harm it. do it quickly and quietly cus ifsome one report u to the Deparment Building Safty they will ask u to tear it down and build it with a permit and with a licenced contracter .whick will cost $$$$$$$$$$$$$$$$$$$$.

if u see anty exposed dirt under it cover it with a lyer f cement o the termits don't eat ur deck again

Answer 9

I would put them 12" apart.

Answer 10

you might want to go with 2x6`s