Deck repair question

[tvgordon]

Bob,  The I-beams stick out from the house and support the board that the joists attach to.  I called it a rim joist but that must not be right because it seemed to confuse folks.  So the joists and the beams run in the same direction.

Cheese,  How do you get the photos on here from your iphone? I took the photos off my iphone and put them in iphoto, but cannot seem to attach them here.  I tried drag and drop and searched for the img number to attach here with no luck. 

Seth,  Thanks for the info on getting photos uploaded but I'm still not having any luck.  If cheese doesn't have any tips for me I might just email them to you.  Or just show you at the next Festool Connect [laughing].  And yes, the beams are perpendicular to the house wall (which are vertical!)

Tom

 

[semenza]

Here are Tom's pictures. Sorry for the delay.

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Seth

 

[peter halle]

Are there 4 steel ibeams under your deck - 2 straight - parallel to the joists and then 2 diagonals out to the outside corners of the deck that extends further out?

It would be fun to see what the framing looks like above the basement ceiling.

I am asking because I want to send images to my architect brother who usually does all his own engineering before having it reviewed and stamped by others (35 years experience).

Peter

 

[tvgordon]

Peter,

The beams that run parallel to the joists extent all the way under the house, but the two smaller diagonal beams only extend a few feet into the basement. 

The previous owner gave the the architectural drawing for the house but I haven't unrolled them yet to look at them.

Thanks Seth for posting the pictures for me,  I hope it clears up what I've been talking about.

Tom

 

[semenza]

Maybe do a little more investigating of the rot.

  I think I would try removing a couple of the deck boards so that you can get to the 2 x 8 joists in a couple spots and see how far the rot goes. If it's not too bad then maybe just do the deck boards for now. Try to pick the worst looking spots to check. No loss since the deck boards need replacing anyway. Also you might want to replace them with wider than a 2 x 4. That way if you come across a bad spot in a joist you will be more likely to be able to span the bad spot and not have the whole width of the  2 x 4 in the rotted place. If the joists are too far gone you can re-figure at that point.

Seth

 

[kevinculle]

OK now this starts to make sense, the deck is indeed cantilevered but the structural members that carry the cantilever are steel I-beams...the pictures are a bit unclear but apparently the I-beams are 8" deep set on diagonals with the 2x8 joists of the deck let into the web of the I-beams.  I can't imagine that this construction would have been permitted without signoff by a structural engineer, but who knows depending on the jurisdiction.  Your objective should be to replace any unsound joists with attachment details replicating the original construction.  You would also be well advised to refresh the I-beams with a coat of high quality finish for corrosion protection.

 

[tvgordon]

Thanks,

Kevin the 2x8's actually set on top of the steel beams. I also plan on painting the steel beams because they do have some surface rust.

 

[Holmz]

Thanks,

Kevin the 2x8's actually set on top of the steel beams. I also plan on painting the steel beams because they do have some surface rust.

Like with POR15?

 

[rizzoa13]

Ok so now thst you've posted pictures it's pretty easy to give repair advice.

A: you plan to remove and replace all of the deck boards.
        Remove all the decking and sister 2x8s to the rotten joists spanning the rotted areas. You can decide how long the 2x8s need to be based on how deep the rot goes from the topside of the joists down. If a 2x8 is completely rotted through the lay up a full length 2x8 spanning from the steel I-beam tk steel I-beam.

B: you plan to replace only the rotted decking board.
        From the open underside push a 2x8 into the stud cavity next to where you want to sister it that runs the entire length of the span between the two I-beams. You have a few options on how to get it to fit. You could bevel one top side of the board to allow it to turn more easily. You'll still need to beat the crap out of it to get it to turn over as you flip it up. You can rip the 2x8 down say a half inch, flip it in place and shim underneath at the I-beams with something suitably strong. Maybe a piece of 1/2" steel stock.

No matter how you get the boards in there, lag bolt it all together and make sure the top of your sisters boards are flush with the existing framing. Relay your new decking and attach it to any good wood you can.

 

[tvgordon]

I hadn't heard of POR15.  I was going to look for something at one of the home centers or Sherwin Williams.  Is the POR15 system a better than average product?

Rizzoa,

After I started removing the deck boards, and after I had sistered 5' boards to the joists, I found the joists that sit on the steel beams and support the other joists were badly rotted.  So now that I have to replace those boards I might as well replace the joists too.  The span is 22' and the company that gave me an estimate said they would use shorter board rather than a single 22' board.  Would you have an idea where to put the joint where the boards butt up to each other?  I was thinking between the steel beams.  There are a couple places that sell 22' boards but I haven't checked into delivery fees yet.  I would think that, as long as the boards were straight, that it might be best to use a single board.

Tom

 

[Holmz]

I hadn't heard of POR15.  I was going to look for something at one of the home centers or Sherwin Williams.  Is the POR15 system a better than average product?
...

GTS1 The POR15, it is the best and only thing if you are serious. Usually only used for boats or automotive where there is water or salt water.

1) GTS = " google that s$$!"

 

[tvgordon]

I googled POR15 after you had mentioned it.  Looks like a thorough 3 step system.

Any idea how long it would last before needing repainted?

Tom

 

[Holmz]

I googled POR15 after you had mentioned it.  Looks like a thorough 3 step system.

Any idea how long it would last before needing repainted?

Tom

All I know factually is that the cost is not cheap.. But the car guys all swear by it, and the yachtsomen/women also use nothing else.

I am ordering some as the Au supplier of Epifanes also peddles the POR-15.

 

[Naildrivingman]

A lot of suggestions have been posted, but I didn't see any reference to what is really carrying the load. From the pictures, it appears that the rim joist of the deck is carrying the outbound side of the deck joists, while blocking or rim joist of the house is carrying the inbound side of the deck joists. Therefore, sistering may not work everywhere, because you are relying on a strong connection of the existing joist to the deck's rim joist. If that connection is weak, a sister joist will only give you surface area to find purchase for deck board fastening.

The other observation is that if you do too much repair, you may be required to update the entire deck to current code (I.E. all new guardrail).  Do your research before diving in.  I see the potential for a lot of work and it's never fun to do something twice.

Good luck!

 

[WastedP]

Above all, just make sure you do the job right. 

I've been listening to the medivac helicopter flying over our house all afternoon, retrieving casualties from a deck collapse this afternoon, the second year in a row.  The area had a deck collapse of even greater magnitude about a dozen years ago.  All together, these three incidents injured over 120 people.  No inspections and hillbillies that think "that looks good enough" are dangerous.

 

[tvgordon]

Since I figured out that the deck will need to be rebuilt rather that repaired, I've been reading articles on decks and researching different products available.  I certainly don't want to build it twice or build it only to have it fall off the house. 

My wife and I haven't yet made the decision on if we want to keep the deck the same size and style or if we want to make some of it larger and use support posts.  We will have to change the railing to meet current standards.  We also talked about designing it so we could add a screened in porch under it sometime. 

While the original deck was nailed together, I will make use of the metal hardware used now. The stores in my area sell both the nails and screws for the metal hardware, is it better to use screws for their holding power?

Tom

 

[Bob D.]

I would use screws or bolting depending on the connection being made and make sure
that the fastener material, be it stainless or galvanized or something else, is compatible
with your choice of decking material. I am dealing now with my house which has a large
deck that was built just 2 years before we bought the place (1998). The screws used are
all rotting away and over the past few years I find a few deck boards have loose and I
have re-secure them. I've been using coated deck screws for that. My deck is low, only 18
inches above grade which probably contributes to the problem due to the higher moisture
level near grade and little room for air to circulate beneath the deck, but pressure-treated
wood can eat your nails or screws up too. I would try not to face nail (or screw) if possible.
Any penetration through the face of a deck board is just a path for water to get inside and
do damage.

If you think you might want to convert some of the deck to a screened-in porch later
on then design your support system for that additional load now, including snow load
if that's a concern in your area and don't forget wind-loading now that you will have
a surface (the underside of the roof) that wind forces can act upon.

 

[kevinculle]

Either the screws or nails designed to be used with joist hangers and related deck structural supports will provide plenty of strength and meet codes.  I have recently redone two decks I originally built 30 years ago.  On both I made some changes that involved revising the framing underneath.  Removing the 10d galvanized nails in those joist hangers was quite difficult and they showed no loss of holding power.

If you go the nail route I would strongly recommend using a compressor and one of the "bang-bang" palm nailers that magnetically hold the nail while you align the tip with the hole in the hanger, then you just press and it drives it in.  Much easier than swinging a hammer in those tight confines.

 

[tvgordon]

kevinculle,  I do have a palm nailer.  That would be good for nailing into the hangers, although I do like the idea of using the screws designed for the hangers too.  The nails on the house do not show any corrosion but there isn't much left of some of them used on the outer section of the deck.

Bob,  I wasn't clear, but I was thinking of adding a screened in porch under the deck.  The deck is on the main floor over a walk out basement. 

What are some of your favorite hidden fastening systems for wood (cedar)?  I would want something that it would be possible to replace a board without taking up the boards around it too.  A while ago I was looking into Kreg's system, but it seems there are several other systems on the market too.

Tom

 

[peter halle]

If you go with screws versus nails for "hangers" so to speak, make sure that you are using hangers and screws from the same manufacturer so that you have an assembly.  Last thing you would ever want would be a catastrophic event and then have brand a not compatible with brand b.

If you were to consider the Kreg system - don't.  Very time consuming.  The Camo system does the same thing, is mor readily available and is quicker.  I have used both and posted my thoughts here about the Kreg years ago and did a deck a month or so ago with the Camo for the first time.  Fewer steps = less time.

Peter