Open Web Floor Trusses, One Year Review - Would We Use Them Again?

No posts, no beams, no wall, no bulkheads...our main floor and our basement are totally open concept with flat ceilings thanks to the open web joists we used for our floors.

It's been over a year since we moved into our home, and wanted to talk over the pros and cons of using these open web floor joists in our home before we covered them up to finish the basement!

If you're building a custom home, this product is definitely worth considering if your homes design is one that can really reap the benefits brought by the lack of posts, beams, and bearing walls. BUT, at nearly double the cost of a conventional floor system, you need to weigh out whether or not your money is better spent elsewhere in the home.

Find Mitch:

Connect with Mitch:

[jeremyenglish]

The engineered trusses can be designed for all types of flooring applications. These trusses are probably designed at code min which is a LL Deflection criteria of L/360 (or 1" over a 30' span.) Most of our floor truss designs are utilizing L/480, and if you have any type of stone tile such as marble or slate, it is required to have a L/600 plus requirement under Total Loads (some applications require less than 1/8" over the span of the floor.) Gypcrete which is used in most commercial buildings requires a total load deflection of L/360 which is also high standard than normal code. The Total Load deflection Criteria under Code is L/240. You also have to consider that you are clear spanning over 30 feet. The material in the trusses could have been increased to a high MSR material or even double chords which would also take away some of that bounce. There should also be three rows of strongback bracing which will aid in vibration and "bounce." This is the "best" system for any application that you want to have less beams and posts, but it does cost more in the beginning (or is was until fire codes required that the basement ceiling be finished if installing them in this area.) The look good, and everything is able to be hidden. Some of the other trades need to be involved during installation to allow them to install the long runs while installing the trusses. This will eliminate the need to drill or cut out holes later. I enjoyed your video.

[shellyd]

You did a really good job explaining the pros and cons of using web trusses and giving good examples of when it is maybe a better choice to use them (or not). Not everybody is so good at explaining things and doing so in a concise way. Thanks.

[allyharry]

I’m glad you considered ‘all things’. Literally every thing in the world that there was to consider and you thought about it. That was very considerate.

[JamesLandolt-me]

Great video - I like these "one year later" videos by the owner as once you lived in the house its a great time to review what you would have done differently. As an owner builder - twice - you are always thinking about what you would do differently if you would do it again knowing that there are a lot of decisions you need to make up front - so you would never build a "perfect" house and I think that is one of the more enjoyable aspects of a custom build and sharing it with others and learning from others.

In regards to a basement - I would agree that you don't need open truss design. More than any other floor in the house you know there are going to be internal walls and you know where they are going to be up front. The furnace/hot water heater area and any storage area, any rough in bathroom areas, and any areas with windows that would meet code for a bedroom.

[truthseeker-vl]

thanks for giving such a clear summary of the positive and issues

[RobertM]

Nice video. Your explanations and thought process are so clear and well articulated I wish every building the video was like this.

[James-opls]

Flex in your floor is it good thing. Good for the joints. There's quite a few others touting this especially when compared to a concrete floor

[luismonroyRealtor]

Thank you for this video, i'm studying to become a home inspector and needed this explanation!!! You're the man!

[chuckhaugan]

I was a mechanical contractor for 32 years with a large, one stop shop, mechanical contractor. Open web truss systems, of any type, including TJL's are preferred to TJI's. The key with mechanical contractors is preplanning and coordination meetings to square up routes. Working on the commercial side, we BIM everything and I do know, BIM is becoming a thing in residential markets.
In general, the truss company should provide truss drawings to the subs long before the slab is poured or the trusses are even in production. Designs are coordinated, pipe, ducts, are prefabbed and when the trusses are rolled and set, pipe is placed in the appropriate void and life moves on. All of that is done prior to "dry in."
Once dried in, installers come back and slap the systems together. It's actually a fast process if guys are smart enough to prefab and the HVAC contractor uses a shop to seal the ends and seam of the duct work. Fire sprinkler guys have no issue if they are installing steel, as that's the norm or CPVC. Long runs of cast for DWV or copper, if the building is secure, for the plumber's supply lines is also no issue.
These systems shouldn't be any problem for a experienced tradesman, even in residential construction. Also, there should be savings in the mechanical systems due to less drilling but, then again, residential is a different animal.

[roberthughes]

Great info and tips. Had no idea they had to be 24" tall. Wow😮

[Rew]

3:45 I totally agree. In a "modern ranch" or "modern prairie" type of home that I'm envisioning, even though the viewout or walkout basement is very important, I don't think it's SO important that the main level should have flooring issues. And you're not going to have an extremely open basement layout - it's going to be relatively boxy because you want several bedrooms down there as well as a bathroom and kitchenette. I think I'll just do much shorter trusses to ensure the floor of the main level is ultra stiff.

[ragibby]

Love the Blackhawks hat! "Here come the 'Hawks, the mighty Blackhawks!"

[phillipstallter]

Bouncing was an issue in our kitchen. Movement was accentuated at the top
Of the fridge and tall China cabinet. Ended up adding support in that area

[tomswinburn]

Wouldn't the "bounce" you talk about be eliminated by using a strongback right down the middle?

[stefcep]

I installed these in my house. No bounce as I installed strong backs. My advice is get your ducting and plumbing runs planned out from the beginning. My plumber took advantage of the open webs and ended up installing his pipes wherever it was easiest for him to do and cut off the preferred ducting paths.

[MegsCarpentry-lovedogs]

The bouncing you talked about appears to be eliminated now by the addition of placing one, two or ? 2x6 board in the center of the open web. The span table indicates this and how many of these 2x6's are needed pending the span. Hope that helps 🙏🇨🇦

[boedillard]

I have no idea if you made the right decision or not but I have to really say the ductwork and wiring seems to be something to consider. I'm new to construction but wouldn't you have to make your basement about a foot deeper with other products to support the ductwork and also make your stairwell longer or make the steps shorter. Also you'd need a lot more support columns.

[ToIsleOfView]

Great points. Only experience and an eye to detail can point this out. I would like to point out that this has a fire risk. All that open space allows a fire to spread very quickly if it gets into the joist space. Insurance companies are looking at this.

[BradleyKerr-ddvf]

Truss design has 3 criteria for stiffness. Depth of truss, spacing of trusses and grade of lumber used. If you do not want a bounce in your floor, design it better! L360 is a very low design for stiffness. You should have used L480 or L600 for your design if you did not want a bounce. Its not the trusses, its the design. No matter what floor system you use, if not designed correctly will have bounce.

[spazoq]

I am considering doing this to my main floor in the basement, as I want to do a home theater in the basement in the future, and I think this would allow an optimal HVAC design for house while allowing me a flexible future layout of a rather large (28'x20') high ceiling home theater room with soundproof wall and ceiling design. Also, why didn't you have these trusses designed with a built in return slot? I've seen some like that, they frame a very large hole through the entire run in one section that the HVAC guys can then box in as the cold air return.