Thank you Gene for providing a clear and concise explanation. Very helpful. I am grateful.

great explanation

Gene, Thank you for posting this. This will definitely help folks, "professionals" & do-it yourselfers alike, get much better results. One thing I would add, for the benefit to folks that this is new information to, is that backer rod comes in several standard sizes: 1/4", 3/8", 1/2", 5/8", 3/4", 7/8", 1", ect. Select the size that's just large enough to fit snuggly to stay in place. I'd also inform folks that it's widely available at the big box builders stores and most well-stocked neighborhood hardware store. I might also add that there's nothing particularly magical about foam backing rod. It's just widely available, easy to use, and the roundness provides the ideal shape. But, in a pinch, firmly stuffing ANY material (fiberglass insulation, rolled up paper, whatevers on-hand) is better then fat blobs of caulk. But, this foam backer is the best solution. Off topic but pertinent: Support your local hardware stores! Folks have been convinced that prices are SO much cheaper at the big box "builders" stores...but, that's often false. And even if their prices are a teensy bit cheaper does it really make any $ence to drive 5 miles, walk a half mile in a warehouse store, and encounter employees that have a "do you want fries with that" attitude and no knowledge about their inventory? These stores are huge, but they're basically large areas of the same inventory. A mom n pop hardware store often has a wider selection; they stuff every nook n cranny with different products. Their prices are usually cheaper too. Think about it: their grandparents built the store...it's paid off. Whereas a big-box has to charge enough to pay for a brand new, pointlessly large, store...and advertising...and team sponsorships...and CEO's absurd salaries. You'll save a ton just on gas going to your neighborhood hardware. You'll park right near the door. You'll encounter employees that know exactly where the items you want are located. Often you'll get expert advice (frequently these employees are retired professional tradesmen). And often their price will beat the big-box. And, by the way, real licensed builders, plumbers, electricians, don't usually shop at these "builder" stores.

I think you just explained why the caulking in my shower barely lasts 6 months 🙃

Super helpful to this newbie. Thank you.

What if your total joint depth is only around 3/4" and you're caulking to fill only small cracks? Backer rod still needed?

I want to use the backer rod on a cement driveway and chalk it. That way, I stop having to deal with my joints turning into flower pots for weeds. I have used sand for 20 years, but every summer, my joints get weeds. Can you be more specific to my situation? Please.

Great job!

We just had foundation work done. Lifted the gap bigger.

That’s incredible, I had no idea about some of these but it makes sense. So what do we do with old buildings, especially historical ones? We can’t adjust many, so what can we do to avoid combustion with highly flammable materials?

Wow, although we don’t see many taking on his inspiration it just makes his work all the more unique. It’s interesting to see the possibilities while respecting historical elements.

Wow I had no idea they took breaks building it. I’m wondering how the lead didn’t damage it as it leant on it over time, maybe it was just a short period? Lastly, I would prefer knowing it’s straight and safe but I’m glad they monitor it, I’m surprised only a degree is enough.

The diagram of the backer rod & caulk was a great addition to your explanation, making the concept CRYSTAL CLEAR. Some folks need that VISUAL depiction along with the verbal. ❤

That is fascinating!! I could see a student trudging through a textbook to memorize those things for an exam, but you made it all into an interesting story. Thank you for bringing history to life by telling it so well. 🙏

The original Usonion plans were circular.

oh i would love to have you as a teacher in any subect! so well spoken and makes me invested so quickly! thank you for these 5,5 minutes!

I was just thinking about how cool it would be to build an amphitheater for Socratic discussion, and then it occurred to me that I bet that is how the Roman Coliseum got started, growing from the inside out, and that was your first example. Cool video.

Thanks! It's midnight, I was just about to caulk my first ever bit of silicone to get the job done but I'm so glad I looked up what backing rod actually is 😅 Seems like another trip to the hardware shop is on my to do list tmoro 😅

Thank you.

That’s a different situation and I can’t really offer a solution from here. You may need some trim.

Can this be put between a brick wall and laminate floor? Whoever put the floor down left a big gap between the wall of the building ( I live in a conversion) and the floor someone tried to put the scotia but doesn’t work because of heating pipes are exposed and low. I thought this might be a solution? Many thanks

If my control joints are 3" deep but my backer rod is just 1 or 1.5 inches tall, do I need to fill the void underneath the backer rod with sand, or can I leave it empty? In the pacific northwest where it barely freezes.

Thanks! Glad it’s helpful.

Best explanation I’ve seen.

Thanks! I just ordered some 1/4” backer rod to fill a gap between the sink and a cabinet .

No! But I’ll look it up. Thanks.

Have you ever seen the Powers-Taylor building in Richmond Virginia ?

Thank you

VERY GOOD !

Long time no hear! Hope you're doing well!

Yes they leak, but only after 50 years.

Great video Gene!

I've had the pleasure of sitting in an inglenook on a winters day, drinking tea, eating biscuits (cookies) and reading a good book, it was glorious.

Who is this?? Bring back the other guy!!!!

Gene looks different today…

Awesome fill in Ben! I'd like to see you and your Dad do a video together! It's not too late to cast that horse head!

Thanks for the video!

Thank you. Man, this is a problem because all I did was make sire I had at least 1/4 expansion gap. But this varies wildly from plank to plank-up to a half inch, because in the basement the drywall is raised. (For context, I'm not using quarter round- I took off the baseboard and plan to put that back to cover the gap.). Anyway, in my case, I dont see how the backer rod will help based on what you explained because in most places, it can't touch both the plank and the stud. I know I should have educated myself on this ahead of time but, well, here I am. Here is the best visual I can give using text: W|=wall side o = backer rod |P = plank edge Ideal: W|o|P Mine, half the time: W| o |P Again, *some* planks are ideal, but most are not and some are severely unideal. This varies literally from plank to plank. The reality is that I cannot undo the flooring I have done. I just finished today. Given that less-than-ideal-situation I put myself in, is there a better-than-nothing approach to sealing? One that won't fill me with utter regret? Lol I appreciate any constructive comments here.

Sir you are 👍

Hello, what would a chimney look like on one of these? I would like to make one but have no idea what I would see if I looked up into one of them

Thank you for your video. Do they make a larger size backer rods for larger sized gaps?

Isnt it 1.618?

So by this definition, almost all sporting venues are amphitheaters.

Where I grew up (Philippines) we have always had bamboo homes. It’s ideal in tropical climates.

That was funny. You can't please everyone. :)

thank you. do you want the backer rod to be the exact size as the gap or slightly bigger. for example, if your gap is 1/2 in wide. do you buy backer rod 1/2 in or 5/8 in?

This is great! Thanks for sharing. As a web designer, I find Vitruvius' three principles applicable to websites as well.

I appreciate your information. Thank you.

Always interesting. Thanks!

Would love to hear more about historical architectural curiosities like this!