How to Install Fiberglass Insulation | This Old House

all right i'm going to take this first bat here and i'm going to go to this nice open bay right here and make sure you start here at the top and then make sure the top is really pushed up nice and tight and even and when you're installing it when you're coming down don't push it in too much or you're going to compress the r value we don't want to do that you like it nice and fluffy yup and then you're going to bring it down here to the bottom plate here and we're going to cut it along the bottom plate right here just a little bit longer than it needs to be so we get a nice good friction tight fit so no tape measure just cutting it in place no i'm cutting it all by eye and um move on to the next bay here all right here's the second one thank you looks like you got a system where you lay it out just in the right spot and move your way down now in this bay we've got our first obstruction we've got ourselves an electrical box yeah how you going to handle that right here you don't want to just cut the outlet out you want to make sure you get against here you pull the bat and split it make sure you tuck behind the outlet and get in there nice and tight so we have no cold drafts coming in then you slice the bat above the electrical box here and then below here take this little piece here curl it in nice and tight so we've got a full width bay but we've got two air conditioning lines running right down the middle how you going to handle this well we used to take the insulation and just tuck it behind here the whole bat but we can't do that anymore because it compresses the r value you won't get the proper effectiveness of it so we take it and we split the bat here in the middle like this and pull it down the entire line down the whole length making sure you get it nice and even so you get both parts yep two thinner bats yup you take this piece here pull the pipe out tuck it behind here pull it up nice and tight making sure there's no voids or gaps and tuck it the whole length of the bay all the way down to the bottom here pulling it nice and snug make sure it's in there nice and good take the other piece here i love it just lay it on top yep all right so we've got the same obstruction in this bay and then we can just work our way right around the room it's real important that we insulate an air seal around all the windows with low expansion foam made for doors and windows so you've got the professionals version here you've got this fancy applicator tip or you can get a consumer version with a plastic applicator but we want to make sure whatever one we get that it's low expansion foam because you got a chance of bowing the windows some foam expands too much yes and you don't want to bowl the windows or you won't be able to open them right correctly will be sealed yes they will you want to start at the top and go slow work your way down and make sure you're filling the whole cavity with foam okay we took care of the walls we took care of the windows now we need to take care of the area above the walls up here they're called blockers i've already cut some pre-cut to fit between the joists just gonna stick them up in here tuck them up nice and tight make sure there's no void all right that is the last one so dave let me ask you a question up top on these blockers we are using fiberglass bats with a paper face and this is the vapor barrier yes it is yep and we like vapor barriers because well in this climate in the winter we've got warm moist air and it's trying to get out of the house and we don't want it condensing on the fiberglass making it wet so the vapor barrier helps prevent that exactly why have you got a vapor barrier up there but no vapor barrier down here well ideally i like to cover the whole wall with a continuous vapor barrier i'm gonna pull the poly tight all the way down to the bottom here all right staple the bottom here all right now dave what about our windows though we've got them completely covered here yeah we're gonna cover those we're gonna leave this up until they're done doing the drywall they'll protect the windows okay looks pretty good right yeah and we got a little bit of everything right for insulation we've got fiberglass and foam and for vapor barrier we've got paper and 3 ml poly and that's how you insulate a wall

Channel: This Old House

Views: 653,953

Keywords: This Old House, Ask This Old House, DIY, Home Improvement, DIY Ideas, Renovation, Renovation Ideas, How To Fix, How To Install, How To Build, how-to, Episode, TV Show, Television Program, Fiberglass, Thermal Insulation, Glass Fiber, insulation, Installation, this old house episode, all new this old house episode, this old house all new, new episode, fiberglass insulation, how to install fiberglass insulation, installing fiberglass insulation

Id: OWQpsbILOPs

Length: 4min 7sec (247 seconds)

Published: Sat Jul 26 2014