Woodworker help & thoughts needed for our new trailer deck

[ebinmaine 71,748]

One of the modifications I'll be doing to our new trailer is adding multiple tie  down points. 

 

I'll be using flush/recessed D rings on the deck. See pics below. 

There will be 12 of these. 6 per side. Approximately 20 ish inches in from each outside edge.  

They'll be attached to the steel cross members at two of the four holes per ring. 

 

The main question I have is:

Should I drill a 3+ inch diameter hole all the way through the deck boards? Or learn to use my router to make a "pocket" and drill a small centered drain hole in the pocket?

 

 

What say you, oh Redsquare gurus??

 

 

 

 

[Pullstart 65,659]

For moisture and draining purposes, I’d suggest a pocket, and a drain hole in the center.  

[953 nut 59,138]

     If you haven't already purchased the flush mounts I would just use the surface mounted "D" rings. They don't stick up that high and won'6t capture water leading to rotted boards.

[Wayne0 1,101]

I really don't think it matters as long as water doesn't pool and soak.

Myself, I'd blow a hole right through to avoid any water sitting there. Is the decking PT?

Edited Wednesday at 11:20 PM by Wayne0

[Handy Don 13,642]

17 minutes ago, Pullstart said:

For moisture and draining purposes, I’d suggest a pocket, and a drain hole in the center.  

And once you’ve routed the pockets, drilled the drain hole (⅜ or ½”), and drilled the mounting holes then, even though the deck is pressure treated, apply a good wood sealer liberally before mounting the rings. 

Edited Wednesday at 11:22 PM by Handy Don

[ebinmaine 71,748]

2 minutes ago, 953 nut said:

     If you haven't already purchased the flush mounts I would just use the surface mounted "D" rings. They don't stick up that high and won'6t capture water leading to rotted boards.

 

I went with the four bolt flush mount hold downs for the ability to have a flat deck.

 

The extra strength is a bonus.  

[ebinmaine 71,748]

2 minutes ago, Handy Don said:

apply a good wood sealer

 

Brand preferences??

[Handy Don 13,642]

7 minutes ago, ebinmaine said:

 

Brand preferences??

For years I used a now-banned, high VOC preservative.

Lately, I’m using Thompson Water Seal which works well. As with most similar VOC-compliant clear products, exposure to the sun does diminish its effectiveness over two or three years. Areas not in direct sun are good for 3-5 years. Preservative stains with suspended solids (e.g. “paint stains”) last much longer.

Edited Wednesday at 11:32 PM by Handy Don

[JimSraj 505]

Since the part that will be recessed isn’t round, I’d make a template that’s slightly larger than matching the shape of the part of the hold down that will be recessed, including the bolt and nut. Fasten the template to the deck and rout in steps until you are deep enough, using a  plunge bit with a flush bearing.  If you want to make the top of the flange flush with the top of the deck, make a second template matching the outside of the 4-7/8” x 4-1/2” with radiused corners. Set the hold down in the routed recess and trace the flange. Fasten second template and rout to match thickness of flange. Drill your holes using the hold down to guide the drill. Drill your drain hole if you like. 

Make sure your template is thick enough to allow you to start the first pass with the bearing on top of the cutter. 

Edited Wednesday at 11:39 PM by JimSraj
Added text

[JoeM 8,136]

My cargo trailer has holes all the way through from the factory.. 

[Beap52 1,330]

Looks like carriage bolts are what will be used to fasten them to the floor.  I'd suggest countersinking them deep enough that Tina or her mom could use a square point shovel to scrape the floor and not catch the side of the D ring assembly or the carriage bolts. 

[ebinmaine 71,748]

6 hours ago, Beap52 said:

Looks like carriage bolts are what will be used to fasten them to the floor.  I'd suggest countersinking them deep enough that Tina or her mom could use a square point shovel to scrape the floor and not catch the side of the D ring assembly or the carriage bolts. 

 

Whether I drill a through hole 🕳  or make a pocket I'd planned on a flush set for the assembly.  

Good idea on the shovel. That's a realistic possibility. 

There was someone on YT that mentioned going to get appliances as his own example.  

I mentioned that to Trina. Her response was a reminder that it would be more stable for getting boards if the deck was still flat.  

It also greatly reduces the opportunity for a tripping hazzard. 

 

 

[ebinmaine 71,748]

I heard back from etrailer.com and found their answers interesting. Figured I'd share here.  

 

 

On 6/11/2025 at 8:40 PM, JoeM said:

My cargo trailer has holes all the way through from the factory.. 

 

⬆️ ⬆️ ⬆️ ⬆️ ⬆️   This is their standard recommendation and procedure.  

They appear to feel that a small drain hole with a routered pocket has approximately the same effects on strength as a single larger hole provided a proper backing of the wood is used. Either a plate or large washers are suitable.  

 

 

On 6/11/2025 at 10:16 PM, Beap52 said:

I'd suggest countersinking them deep enough

 

 

 

They do NOT recommend removing any surface material from the board to get the D ring holder set into the board for a flush surface. 

That removes  +/-  10% of the wood which changes the strength of the surface along with the long term rot resistance even when coated. Remember that modern Pressure Treated has more treatment at the surfaces.  

 

 

On 6/11/2025 at 7:29 PM, Handy Don said:

For years I used a now-banned, high VOC preservative.

Lately, I’m using Thompson Water Seal which works well. As with most similar VOC-compliant clear products, exposure to the sun does diminish its effectiveness over two or three years. Areas not in direct sun are good for 3-5 years. Preservative stains with suspended solids (e.g. “paint stains”) last much longer.

 

 

ALL CUTS are to be treated as stated above in this thread.  

 

[JoeM 8,136]

2 hours ago, ebinmaine said:

They appear to feel that a small drain hole with a routered pocket has approximately the same effects on strength as a single larger hole provided a proper backing of the wood is used. Either a plate or large washers are suitable.

I pretty sure mine have backer plates on the bottom. Those may even come with plates??

 

[ebinmaine 71,748]

3 minutes ago, JoeM said:

I pretty sure mine have backer plates on the bottom. Those may even come with plates??

 

 

 

You can get them with or without the backer plates. I chose to order mine without the plates because I am mounting them partially to frame rails. Fasteners that don't go through a frame rail will get doubled up or extra thick large diameter washers.

[JimSraj 505]

What thickness boards are you planning to use? If you are planning to use PT lumber make sure to use ground contact rated  boards. My personal choice would be seasoned locust or white oak. IMHO the PT available today is pretty poor. 

[ebinmaine 71,748]

3 minutes ago, JimSraj said:

What thickness boards are you planning to use? If you are planning to use PT lumber make sure to use ground contact rated  boards. My personal choice would be seasoned locust or white oak. IMHO the PT available today is pretty poor. 

 

 

This is on a brand new trailer.

 

 

I agree with you on the PT quality nowadays. Like many other things, regulations changed the way it was processed.

 

If we get to a point that we need to replace the boards I probably would try to get white oak.

Locust basically doesn't exist around here. White Oak is rare and expensive but attainable. Hemlock is another possibility.

 

 

 

[oliver2-44 10,553]

14 hours ago, ebinmaine said:

 

I agree with you on the PT quality nowadays. Like many other things, regulations changed the way it was processed.

 My Brother in Law has a place at the coast on a canal. He recently had a canal bulkhead put in and they used PT lumber. We went to the local Bay City Tx Lowes for some additional lumber. The PT they stocked was really green looking like the old stuff used to be. There are.some salt water worms that would eat the normal treated lumber. So I learned there are several grades of treatment of PT lumber. Most places just stock the lowest cost one. 

[ebinmaine 71,748]

7 hours ago, oliver2-44 said:

 My Brother in Law has a place at the coast on a canal. He recently had a canal bulkhead put in and they used PT lumber. We went to the local Bay City Tx Lowes for some additional lumber. The PT they stocked was really green looking like the old stuff used to be. There are.some salt water worms that would eat the normal treated lumber. So I learned there are several grades of treatment of PT lumber. Most places just stock the lowest cost one. 

 

 

Good point and thanks for posting this. 

 

Up here we can get two Grades of PT. 

They're based on the BOARD just like buying plain pine. .... because it is pine.  

 

We have a local Pressure Treating facility that ships at least all over New England. 

Another down in Massachusetts I believe as well. 

 

 

 

 

[Handy Don 13,642]

Yep, nationally there are several grades of PT but in our area the big box places stock only “severe weather” and “ground contact”.  The yard that’s been catering to builders for the last 100 years will order anything you want, though (and they’ll help you decide). 

Note that lots of PT lumber is not suitable for any structural purposes. I got grief from the building inspector when I laid my deck boards at an angle to the supporting joists which made the spans longer than 16 inches. I had to show him the specs for the deck-specific stuff I was using to prove that it met the code requirements.

[Wayne0 1,101]

On 6/13/2025 at 9:12 AM, ebinmaine said:

 

 

This is on a brand new trailer.

 

 

I agree with you on the PT quality nowadays. Like many other things, regulations changed the way it was processed.

 

If we get to a point that we need to replace the boards I probably would try to get white oak.

Locust basically doesn't exist around here. White Oak is rare and expensive but attainable. Hemlock is another possibility.

 

 

 

Another option would be Doug Fir. Strong and very rot resistant.