Browse Forums Heating, Cooling & Insulation 1 Apr 28, 2014 6:44 pm Hi Guys, I intend to insulate my floors using pink batts and have some questions. My house has timber floor boards covered with lino above a tall and easily accessable subfloor. I understand that I will just be jamming the pink batts (of appropriate width) between the flooring joists and supporting them there. What I am not sure of is whether or not to use "sarking" (I think thats the right word). My dirt subfloor is a little damp due to living on a slope so I am concerned about moisture and mould etc. I have read that using insulation can cause moisture to gather due to a temperature differential. Is this what sarking is intended to prevent? If so, how do you use it? Should I be fixing the sarking to the underside of the timber flooring before jamming the batts in? Or do I use the sarking to hold the insulation in place, effectively sandwiching the insulation between the sarking and the underside of the timber floor? Is the sarking even necessary? Am I over thinking it ? I have also read on an American site that the dirt subfloor needs to be covered with plastic sheeting to trap the moisture in the ground. I have never seen or heard of this being done anywhere else, is it overkill ? Also, I have heard that commonly insulation is (or was) held in place using chicken wire. I could do this but I am considering more cost effective options. One idea I had was to string very thick fishing line under high tension between screws on the joists back and forth to hold the batts in place, sort of like a primative web. Are there better solutions? Anyway, any advice would be appreciated. Re: DIY Pink Batt Floor Insulation 2Apr 28, 2014 10:26 pm Have you looked at Expol? http://youtu.be/hVr_GGxaib4 http://youtu.be/_vndQExj73g Otherwise here are some instruction on how to install batts underfloor. Just make sure you buy the underfloor ones. http://youtu.be/eVQL4WqkW8E Re: DIY Pink Batt Floor Insulation 3Apr 29, 2014 12:21 pm I would look to install a product similar to Foilboard or Expol to help remove the possibility of vermin taking up residence. Peter Clarkson - AusDesign Australia www.ausdesign.com.au This information is intended to provide general information only. It does not purport to be a comprehensive advice. Re: DIY Pink Batt Floor Insulation 4Apr 29, 2014 5:58 pm I see that the Expol stuf has an R value of 1.4. Is this going to be enough to be significant? Is the difference after installing any underfloor insulation noticeable ? Re: DIY Pink Batt Floor Insulation 5May 03, 2014 12:37 pm For floors I'd be looking at a minimum of R 2.0 but that depends on how well the rest of your house is going to be insulated as well. No point spending big on floor insulation if you have skimped on the ceiling. Solid foam sheets cut to fit between the floor joists are the way to go. 2400 x 1200 x 50mm thick poly sheets ( R 1.8 - R 2.0 ) can be bought for $22 a sheet. A couple of nails either side is all that is needed to hold them in place. I should mention also that rather than laying plastic over your sub-floor ground area , I'd try and eliminate the source of the moisture first by way of good site drainage around the perimeter of your house. Stewie Re: DIY Pink Batt Floor Insulation 6May 10, 2014 8:13 pm I live in a timber house sitting on steel posts on a very steep slope. It has t&G timber floor boards. It was very cold & drafty in wintertime. I installed R3.5 pink batts between the floor joists. Initially it worked a treat. No more drafts and I was able to heat the house however then possums moved in and took up residence in the nice warm insulated floor space. They are still there now. I have not been able to prevent them from entering this sub-floor space. I don't know what the answer is but I think that when the insulation was installed, the entire sub-floor space should have been completely sealed using breathable sarking of compressed cement sheets. Re: DIY Pink Batt Floor Insulation 8May 10, 2014 10:21 pm Ahh, so thats the reason for the chicken wire vs an easier method (when using pink batts at least). So it looks like my options are solid foam sheets with an r value of at least 2.0 (which seem to be non existant) or pink batt/wool style with chicken wire (more labour intensive but better insulation). Re: DIY Pink Batt Floor Insulation 9May 11, 2014 10:17 am You have to look how well the rest of your house is insulated ( as I mentioned earlier ) bearing in mind that only 10-20% of heat escaping will be through the floor. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ No point having R-4.0 insulation in your floor if your walls and ceiling are only R-2 and R -3. As always it is a law of diminishing returns. By the way if you do your research you will find poly sheets from R-1 through to R-6. Stewie 1 8701 CDC Housing Code 3 When to apply Floor Area external face of wall vs Gross Floor Area internal face of wall. Reading thru CDC Housing Code 3, lets take a lot 915sqm.… 0 11677 isn't a garage level with the rest of the house a given? pretty sure they 'came around' long time ago. if you have a flat block, the garage is usually level with the rest… 1 13366 |