Is it better to compress the insulation and pack it in between the trusses and over the existing insulation? Or is it better to lay the rolls perpendicular to the trusses? If I pack it it, it really compresses the rolls. If I lay the rolls perpendicular, this will cause a 2"-3" gap between the layers and I'm not sure if that is the proper way to do it.
2006-11-09 01:43:02 · 9 answers · asked by cujmh7 2 in Home & Garden ➔ Do It Yourself (DIY)
In any event "do not compress" insulation, blown or loose fill insulation and on the most part all insulation, is designed to capture air and stop it's movement. The insulation value is attained through stagnant air, even closed cell insulation such as rigid foam uses the same principle. You would be best, to add to the original in the same fashion, most "Big Box" stores rent the equipment. That said, place rolled insulation perpendicular over existing in such a way as not to compress existing, by such means as to trap air between both new and old and limiting it's movement. Make sure you are not also adding a vapour barrier in the wrong location. If in doubt, research proper location of VB for your application ...
Hope this helps...
PS: as Lauren mentions "do not block" up ventilation, use soffit baffles....
2006-11-09 02:33:36 · answer #1 · answered by diSota 2 · 0⤊ 0⤋
How To Install Roll Insulation
2017-01-02 19:38:44 · answer #2 · answered by ? 3 · 0⤊ 0⤋
Lay it at a right angle to the existing. Compressing insulation takes out the vital air spaces that make it insulate so you would be doing the equivalent of removing the compressed insulation - not good.
2006-11-09 05:18:38 · answer #3 · answered by Rich Z 7 · 0⤊ 0⤋
DON'T COMPACT IT! The air gaps are what provides the insulating value. Other then that, it really doesn't matter if you roll it out perpendicular or parallel with the trusses. Usually, if you are rolling multiple layers of batt insulation, you would alternate the layers.
2006-11-09 10:06:44 · answer #4 · answered by Jeffrey S 6 · 0⤊ 0⤋
Additional 2" to 3" air gap act also as an insulation so it will not reduce the effectiveness of the insulation. Since probable existing insulation has moisture barrier installed against attic floor it is important to buy blankets without moisture barrier.
2006-11-09 02:57:47 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Roll it over the existing insulation, but make sure you roll it out perpendicular to the joists. That way you won't crush the blown in stuff and loose its insulating value. Also make sure you leave room when your are near the eaves to allow for air flow.
2006-11-09 02:31:35 · answer #6 · answered by Lauren 4 · 1⤊ 0⤋
I would ask your DIY house, because I have heard conflicting opinions on double insulating......some issues with moisture, etc.
I have heard that compressing the blown in insulation can actually draw moisture and damage the attic.
Make sure you allow the space at the eaves for proper air flow too!
2006-11-09 04:29:46 · answer #7 · answered by novamanassas 2 · 0⤊ 0⤋
Just roll it out over the existing insulation
2006-11-09 01:45:46 · answer #8 · answered by peckerwud2 3 · 0⤊ 0⤋
do not compress it u will lose your r value of the insulation. i would just roll it out over top as close to each other as possible. and do not cover any lights this will cause them to get to hot and cause fire also do not block the airflow from your eves into your attic '
2006-11-10 19:06:50 · answer #9 · answered by right answer 2 · 0⤊ 0⤋