Any deck builders? Need decking gap advice

biosurfer1 · 01-20-2018, 12:36 PM

I'm rebuilding my entire 600 sq ft. deck (full thread to come) that was horrifically built originally (to put it mildly).

Anyways, the original deck was built using 2x6 as decking and I'm going with 1x6 hardwood for the new decking, I'm using the existing ledger size so there is a gap I can work with, but I wasn't sure if there should be a small gap between the flashing on the house and the deck boards (see pictures). The first picture is maximum gap, the second is the deck board at the top of the flashing. Should they be pressed up against the top of the flashing (like the second pic) or leave a small gap?

id10t · 01-20-2018, 12:51 PM

Not an expert but I don't think you want contact on either side (top or bottom). Split the difference between what the 2 pics show.

KFC911 · 01-20-2018, 12:54 PM

I'd leave a slight gap on the top clearance and definitely on the edges around the house....but that'a just me....

biosurfer1 · 01-20-2018, 12:57 PM

I didn't get a picture next to a door, but my concern with splitting the difference would be is at one of the doors (3 sliding glass) is there is the door frame, then 1 inch of stucco, the the flashing so if I split the difference, it would add another ~.5 inch.

Its hard to visualize what a ~2.5 inch rise would look like from the deck board to step into the house, but my guess would be to make that as small as possible.

Also, the deck slopes slightly away from the house, not sure if that makes a difference in gap size or not.

biosurfer1 · 01-20-2018, 01:00 PM

One other question, is it usually easier/better to set all the joist hangers then come back through and set the joists or set the hangers with the actual joist all at the same time?

I have a simple jig (in the pictures) so I could do either way.

drcoastline · 01-20-2018, 01:01 PM

My first question is; are your joists 16" centers? with 2x6 decking they may have gone with 24" centers? I don't know I'm asking.

I would re-think the 1x lumber. At very least you are going to have a tremendous amount of bounce and movement. Keep the decking flat on the joist. Pack the gap and put a trim piece over that bridges between the packing and siding. Or pack the gap between the siding and joists and the start the decking at the packing.

drcoastline · 01-20-2018, 01:04 PM

Quote:

Originally Posted by biosurfer1

I didn't get a picture next to a door, but my concern with splitting the difference would be is at one of the doors (3 sliding glass) is there is the door frame, then 1 inch of stucco, the the flashing so if I split the difference, it would add another ~.5 inch.

Its hard to visualize what a ~2.5 inch rise would look like from the deck board to step into the house, but my guess would be to make that as small as possible.

Also, the deck slopes slightly away from the house, not sure if that makes a difference in gap size or not.

Keep the decking flat on the deck. Cut a filler to use as a kick plate between the decking and door sill. The sloe of the deck is correct. That allows water to run away from the house. Should be about 1/2" to 1 foot run. What that means is it slopes down for every foot it goes out.

drcoastline · 01-20-2018, 01:08 PM

Quote:

Originally Posted by biosurfer1

One other question, is it usually easier/better to set all the joist hangers then come back through and set the joists or set the hangers with the actual joist all at the same time?

I have a simple jig (in the pictures) so I could do either way.

I use a cut off place it in the hanger. Set the top of the joist. Hard nail one side to the ledger or box. Let the other side hang. When you set your joists you can easily slide the joist in push the loose side tight to the joist and set it. That's just me nothing wrong with hard nailing the whole thing. The only issue you may have is if a joists is full of water it will be tight going in. May need extra persuasion.

motion · 01-20-2018, 01:11 PM

I can't help with your question, but fun project! My deck project 10 years ago was the first and only "large" construction project I've ever undertaken. Very satisfying.

biosurfer1 · 01-20-2018, 01:15 PM

Quote:

Originally Posted by drcoastline

My first question is; are your joists 16" centers? with 2x6 decking they may have gone with 24" centers? I don't know I'm asking.

I would re-think the 1x lumber. At very least you are going to have a tremendous amount of bounce and movement. Keep the decking flat on the joist. Pack the gap and put a trim piece over that bridges between the packing and siding. Or pack the gap between the siding and joists and the start the decking at the packing.

16" centers, the original deck was 24". If frame would have been salvageable, I would have just replaced the deck boards but the more I got into it, the worse it was. I'm certainly no expert in deck building but even I could see they cut as many corners as possible on the original build.

I'm using a Brazilian hardwood (Tigerwood). I already setup a test with an 8 ft. board over joists at 12, 16, and 24" to make sure it would work. At 24" there was a tiny amount of bounce/flex, at 16 and 12 it was completely solid, even with my fat a$$ jumping on it.

I tried out Tigerwood, Ipe, and Cumaru. I havent been wood working long but it is simply crazy how dense and heavy these south american hardwoods are.

The slope of the joists/decking worked out just like I calculated. I ran the calcs to make sure it would work out, but it's still a little surprising when it actually does

biosurfer1 · 01-20-2018, 01:18 PM

Quote:

Originally Posted by drcoastline

I use a cut off place it in the hanger. Set the top of the joist. Hard nail one side to the ledger or box. Let the other side hang. When you set your joists you can easily slide the joist in push the loose side tight to the joist and set it. That's just me nothing wrong with hard nailing the whole thing. The only issue you may have is if a joists is full of water it will be tight going in. May need extra persuasion.

This is the same plan I had, so nice having the confirmation. I know there are several ways to go about this but this seemed the easiest. Trying to manhandle the full joist and mount the hanger seemed tough, even if the joist was hinged on the beam.

drcoastline · 01-20-2018, 01:20 PM

Quote:

Originally Posted by biosurfer1

16" centers, the original deck was 24". If frame would have been salvageable, I would have just replaced the deck boards but the more I got into it, the worse it was. I'm certainly no expert in deck building but even I could see they cut as many corners as possible on the original build.

I'm using a Brazilian hardwood (Tigerwood). I already setup a test with an 8 ft. board over joists at 12, 16, and 24" to make sure it would work. At 24" there was a tiny amount of bounce/flex, at 16 and 12 it was completely solid, even with my fat a$$ jumping on it.

I tried out Tigerwood, Ipe, and Cumaru. I havent been wood working long but it is simply crazy how dense and heavy these south american hardwoods are.

The slope of the joists/decking worked out just like I calculated. I ran the calcs to make sure it would work out, but it's still a little surprising when it actually does

Ok, as long as you think it will be solid. I didn't want you to get all the decking down and get sea sick every time you walked across it because it bounced so much.

biosurfer1 · 01-20-2018, 01:23 PM

[QUOTE=motion;9893949]I can't help with your question, but fun project! My deck project 10 years ago was the first and only "large" construction project I've ever undertaken. Very satisfying.

Nice Motion.. mine is elevated, more along the lines of the smaller deck you have there in the background.

It has taken me since October, working on the weekends, to tear out the old deck and start the rebuild. The beam footers are the only thing I as able to keep. The original builder didnt do ANY type of water prevention. All of the joists were falling apart, the deck boards were painted and held water so my friend stepped completely through one and thats when I decided, it all goes in the trash.

I have until pool time to finish before the wife starts glaring, but taking my time and learning has been great. I love doing this stuff, just wish I didn't have a job that got in the way!

drcoastline · 01-20-2018, 01:24 PM

Quote:

Originally Posted by biosurfer1

This is the same plan I had, so nice having the confirmation. I know there are several ways to go about this but this seemed the easiest. Trying to manhandle the full joist and mount the hanger seemed tough, even if the joist was hinged on the beam.

You could temporarily screw a piece of scrap to the bottom of the band and rest the loose end on the ledge while you work the other end.

biosurfer1 · 01-20-2018, 01:26 PM

Quote:

Originally Posted by drcoastline

Ok, as long as you think it will be solid. I didn't want you to get all the decking down and get sea sick every time you walked across it because it bounced so much.

That is why I set up the test. I walked on an old composite deck that had 16" centers and even though that is to code and recommendation, it felt bouncy to me. It didn't bother me but I can see where 12" max would be advised on softer wood or composite. Not sure if the capped composites or PVC are the same or not. Too much $$$ for those so never got into it.

I researched for a months before I started. I will be rebuilding this deck ONCE, EVER! If something happens and it needs to be rebuilt, the house will be sold first

biosurfer1 · 01-20-2018, 01:31 PM

Quote:

Originally Posted by drcoastline

You could temporarily screw a piece of scrap to the bottom of the band and rest the loose end on the ledge while you work the other end.

I like your way, should work out fine.

I'm having the joists delivered next week. I'm sure they will be wet, but I've read to set the pressure treated parts wet so they can't twist/check once they are held down, but let the deck boards dry out to make sure they don't (or minimize it at least) before setting them.

I'll be using the Camo hidden fastener system to screw everything down. I don't mind the face screwed look but only if it's done very straight and symmetrical. Plus this hardwood would need pre-drilling to do that. The Camo screws have a built in drill feature in their screws, plus sort of hidden while still being able to remove single planks will be nice.

drcoastline · 01-20-2018, 01:45 PM

Not sure where you are getting the treated lumber from but the beauty of HD and Lowes is the ability to take things back. That being said, if this were a commercial job I would agree hang the $h!t as fast as you can and get out. Since this is your house I would suggest you stack the lumber and let it dry/acclimate a few weeks. If a piece twists, checks, warps take it back and get another. If you cut and hang the treated while wet it is going to shrink significantly and none of you seams will be tight. It may still twist on you.

The treating process is done using high temp high pressure. The lumber is ultra saturated. Normal moisture content is around 12-15%. The treating process can have 40% or more moisture content. It is the drying out process that causes the wood to warp due to uneven drying.

It's best to wait.

biosurfer1 · 01-20-2018, 01:51 PM

I'll probably be getting the PT wood from Lowes or HD for the reasons you mention and just because the local lumber yards are way more expensive. I wanted to use a yard but the two I went to were $280 and $310 more than the big box stores, and I only need about $2k worth of PT lumber for the frame, that's just too much to justify.

The PT lumber I've gotten from HD so far has been fine, fairly straight, some are very wet, others are dry. Amazing difference in weight between the two. It takes a while to crawl around looking for the good pieces, but if I can get them to bring down a fresh pallet, its not too time consuming. to find good ones.

dyount · dyount's Garage

Here's an inspectors 2 cents. Google DCA 6 by the American Wood Council for just about everything dealing with decks. Also Fairfax County Deck Details DCA 6 - Prescriptive Residential Deck Construction Guide
As far as a easy peasy on installing joists by yourself. Install the flange of the hanger to the band board at the house. Install 1/2 the flange of the other hanger. Put one end of the joist in the fixed end and using a ladder lift and place into the one you half nailed. That way if the joist is twisted a little you can get it into the hanger anyway. Then use either a crow bar or put a clamp on the twist and get it to fit in the hanger and nail it. Speaking of nails/screws you can only use what nails or screws that are recommended by the hanger manufacturer. No reason to let the joists dry out just nail away.... or you can order dried/treated/and dryed PT lumber for more $$
If you let an unrestrained PT joist system dry long enough they'll twist like nuts

dad911 · 11:49 AM

1) I would replace the ledger fastened to the house. Looks like it was nailed (not to code) and nails are rusting. Wouldn't surprise me if there is damage behind the ledger. Use ledger locks or equivalent, rated for PT.
2) Aluminum is NOT to be used against PT lumber, it will corrode.
3) EDIT: 2x8 joists, sorry for confusion caused by me.

So I would use rubber stick-on flashing behind the new ledger, and on top of the new ledger to protect the aluminum flashing. As to the gap, I would just fill gap on top of the new decking with pvc trim board ripped to fit.

https://www.lowes.com/pd/TITE-SEAL-Self-Adhesive-Waterproof-9-in-x-33-ft-Rubberized-Asphalt-Roll-Flashing/3055549
https://www.lowes.com/pd/FastenMaster-50-Count-0-to-x-5-in-Ecoat-Hex-Drive-Structural-Wood-Screw/3294886