Why Use RIGID Insulation board On basement walls

[Music] [Applause] I'd like to talk to you guys a little bit about using rigid foam board on basement remodels and on your build-outs best practice for basement wall insulation meaning the best insulator as well as best vapor barrier system is closed-cell spray foam now the second best is rigid foam board especially if you're gonna try to save yourself some money and do it yourself also called extruded polystyrene XPS or poly iso insulation rigid foam boards create an excellent vapor barrier along with an insulation layer that will not promote mold growth the simplest way to prevent this water vapor that we have problems with in basements from entering the space is to prevent air movement or moisture in the air into that basement by installing a solid vapor barrier when properly installed close I'll spray foam spray or rigid foam board acts as that vapor barrier as well as insulates now Polly plastics and craft Faced fiberglass insulation it's not a good vapor barrier in basements the main goal for using rigid foam board against masonry walls is to prevent vapor movement and mold growth now while it can still be used as an insulation or standalone insulation it is often supplemented by a 2x4 wall and fiberglass insulation so what's the best rigid foam board to use while there are two types pretty much a rigid board there's the extruded polystyrene the XPS the blue stuff the dowel and then it's the poly iso insulation board both types work well and are both of them are closed cell boards poly iso is the better choice and poly iso is foil faced and it's most commonly used because of its fire retardant properties under normal fire conditions XPS will melt and drip while poly ISO chars over the poly ISO file face it also helps with limiting of that moisture travel as well it's part of that vapor barrier plecos commonly we see it in roof wall ceiling and specialty applications both in commercial and residential buildings of all types it delivers a long-term stable thermal performance somewhere like our five per inch for value now here's some things that want you to consider compared to spray foam it is harder to install rigid boards especially in areas where there are pipes and other utilities for example a tight space where maybe a rim joist is that close to a parallel joist or maybe areas where there are lots of wiring or pipe penetrations or pipes running along the walls but it is a cheaper and a popular choice if you're going to be doing it as a DIY project if you can consider relocating any of those wall obstructions we just talked about so that you can allow the continuous run of the rigid board and again if you could relocate pipes to the joist space or wires and things like that get them off the masonry and that would be great if you can't relocate obstructions then you're just going to run and start and stop your rigid foam on either side of that obstruction and go back later and fill in that area with closed-cell spray foam I recommend that you use a two inch insulation board on the walls and install them in vertical orientation type to the floor and all the way up if you can or up to the top of the wall or the rim joist of the joists depending on your layout rigid board insulation typically comes with interlocking tongue and groove edges I always try to use those edges fit them together use those factory edges and then once they're tight I've returned later and we tape and seal the seams prior to installing the next insulation board I always had a thick bead of adhesive into that edge of the groove I use the DAP tiny grip construction adhesive it works well with this rigid board stuff it'll also bought two masonry walls dinah grip is a premium high-strength adhesive it's a multi material he civ it delivers powerful instant grab and you want that because you're doing those vertical insulation boards against masonry it also creates a really long lasting Houston adhesion so that's why we use it and we press that insulation board right up against a masonry make sure the masonry wall is smooth lastly we tape all of our vertical seams using foil tape and then we seal the tops this and the bottom edges with a probe spray gun applicator and we use the Gap polyurethane low-tempo messy lint some spray foam and we use that to completely fill all the gaps penetrations air leaks anything not covered by the rigid foam now let's talk about the rim joist in the sill plate area because it might make sense to fill that area first or afterwards it depends on the orientation of your ceiling joist and also your work flow and efficiency the rim joist is located above grade and for many years we treated that similar to wall insulation like we did a buff Laika of 2x4 wall and we would just stuff insulation bats in the rim joist this method is no longer considered best practice best practice for rim joists and the sill plate area is the seal all the cracks against air leakage and then insulate the area and to create that vapor barrier I'll throw a link in the description below about on a video that we did on how to seal rim joists we talked about three methods once the rigid foam is installed it's then time to install a basement wall if you want right up against the two-inch rigid boards you can then add fiberglass insulation to the stud walls and that's going to increase your basement r-value so guys don't forget we did some other videos on best practices in the basement for insulating rim joists wall spray foam clothes spray foam we talked about are you saying a frost pack if you enjoyed this video please consider subscribing give us a thumbs up and check out our other videos we'd appreciate it and also leave us a comment we love hearing from you guys I'm Rob Robillard and we'll see you next time here at concord carpenter you

Channel: A Concord Carpenter / ToolBoxBuzz

Views: 533,354

Rating: 4.9227943 out of 5

Keywords: diy, how to, step by step, tools, reviews, carpentry, remodel, construction, polyiso, insulation voard, rigid board, DAP, Dynagrip, basement insulation, best practice, vapor barrier, insulation board, XPS

Id: S1sfSFWn8AY

Length: 6min 35sec (395 seconds)

Published: Fri Jan 31 2020