How to Install Deck Guardrail Posts | Trex Academy

Installing guardrail posts are essential in creating a safe and functional outdoor space. Learn more about guardrail post installation and spacing with Trex® Academy's step-by-step video instructions.

Key moments in this video:
00:00 Intro
1:04 Corner Post Install
6:53 Front Rim Joist Line / Intermediate Post Install
9:42 Side Rim Joist Line / Intermediate Posts

[snowbank]

Excellent presentation for installation of deck rail posts including how to handle out of plumb posts and using temporary boards to hold post and blocking. Sigh. This gets a fair bit harder to do when the deck is already down and you are replacing half cut outside fascia mounted posts with full inside posts.

[SeanInAlaska]

I am at the point of installing railing and this is by far the best video I have seen on the subject. Thank you!

[eriks]

I've watched a lot of deck construction videos. This is, without question, the best guide for rail post installation. Looking forward to installing my new Trex composite deck!

[eugeneanderson]

One of the best videos out there! Waiting on my Trex decking to arrive as I finish my build. Needed this information. Excellent tutorial

[joeburrier]

I used this method and the posts are far more secure than I expected. Fantastic video.

[ThatGuy-zuze]

I get a kick out of this obsession with "center to center". it makes it easier to line up the next one by corner without having to trying to find the "center" of the next post... But I will say these videos are pretty well done.

[onetwothree]

I've seen this structural screw method becoming more popular. However, I'd note that it is not the strongest blocking method. I'd guess the structural screw manufacturers are suggesting this method because it uses more of their screws.

A better blocking method would use butt the 2x8 end grains up against the post, instead of butting your post up against the weak, flexible sides of the 2x8s. Also, a 4x4 with structural screws is not going to be as strong as two 2x8s (laminated or not) with 6 normal screws perpendicular to the force they are resisting.

Through bolts would be ideal for these installations, but regardless the blocking would be less likely to fail with a larger number of smaller screws, installed only in the direction of shear forces... Which is possible if you butt the ends of 2x8's into each side of the post (and add blocking to the next joist bay too if you're not in a corner)

[glarios]

I learned a lot from your video! Thank you 😊

[GeraldTheMaker]

cannot thanks more for this information! this is the best deck post tutorial you can get on youtube!

[hiebiz]

Excellent instructions, very clear and easy to follow. Thank you.

[prhapsisuppose]

This video is exactly what i was searching for. thanks so much!

[mrrutledge]

One heck of a fastener commercial. I'm thinking the fastners would cost as much if not more than the lumber. Was all that really needed or was it just a clever way to sell multiple sizes of screws? What good are the 8" screws with 2 inches of thread on the corner? Doesn't hurt to over build but this was over kill on the fastener sales. Pretty entertaining though.

[terryjones]

Excellent! The only thing I'd do differently is turn your clamps around so you don't run your leg, (or something else) into them... LOL. You might also mention that different configurations may require you to double your rim joists as well.

[EverythingHasAStory]

very good information and very clear illustration. will follow it. thank you very much.

[bjrnarvaland]

Very detailed and good decriptions. Thanks.

[johnblandy]

Excellent video. It would be nice to know how you block the post next to the the ledger

[chris]

Absolutely great video! I feel like it should have 10x the number of views. I do have another pre-drill question for you. I have looked at the literature Simpson Strong tie has for the Timber screw series and they keep repeating that the design eliminates the need for pre-drilling in most applications. There are certain scenarios where they discuss the use of a 5/32" drill bit, but only in very specific instances. Can you confirm if you used a 5/32" bit and if there was something that specifically made you lean towards pre-drilling or if it is just a general practice you follow on longer length screws? Again, really appreciate this video and really the whole series of videos you put out.

[spelunkerd]

I get the idea of back blocking, to increase the surface area of contact with the post. However over time we all expect that post to shrink, and as it does the secure clamping force disappears. In the past all one had to do was retighten the back nuts on the mounting carriage bolts, but in this case the back blocks are themselves screwed into joists. So to retighten the post connection you'd have to remove those mounting screws to the backblocks before retightening. Why do you even need to fix backblocks with screws into the joists? Aren't they simply acting as a big washer, to increase the surface area of the connection?

[chrism]

It's not necessary to predrill for the 8" screws and impossible to do it level between the joists. It's also important to ensure that the 4x4 blocking is flush with top of the joist if you plan on picture framing.

[spelunkerd]

What do you think about the rigidity of surface mount aluminum railing, with no 4X4 posts? If well secured below, do they hold up as well over time?