insulation question

[Tom L.]

I just received a quote for adding insulation to my attic. There is currently nothign at all up there. The contractor quoted me for R-30 and then a option to upgrade to R-38 if i was intersted. It was about $110 for about 900 sqr feet of coverage. Is this worth it? Is there much of an advantage with R-38?

This a 50's ranch in Northwestern Ohio (currently burried in snow) House is heated by a gas furnace. The area being insulated is over our bedrooms. The insulation is blown in fiberglas.

[Wgoodrich]

I question his accuracy of R ratings with blown insulation.

I would say proper insulation for your attic is to blow in insulation to a level about 2" to 3" above your ceiling joists.

Be sure that bridging is placed along the low side of the roof so that the venting of your attic integrity is maintained as required by Code.

Be sure that you do not cover any recessed lighting that is not approved in direct contact with insulation.

Make sure you do not bury any live old knob and tube wiring which would be a violation of the NEC.

I would get about three bids to compare and that all bids are bidding apples for apples. Be careful about sales pitches that collect more money yet you get little or nothing for the extra money. Know what you are getting for your money. If all else fails go to your lumber company and rent an insulation blower and install your own insulation if you like.

Just some ideas that you may not have thought of.

Let us know how you come out

Wg

[Tom L.]

they said the "r-30" is about 12" deep and the R38 is about 15" deep.

As a fyi our ceilign joists are 2x4 and 2x6's depending on the section of house your in.

I am plannign for the vent baffles.. no can lights to worry about

[Wgoodrich]

The IRC states in N1102.1.2 that if you install your bridges so that the insulation can cover over the top plate of your walls then you may use R30 in place of R38.

In you case Minimum insulation value with 4" truss type construction I would say the R30 would make you surprised at the added warmth. Doubt you will see much added warmth if you went the R38. If you installed the R38 rated insulation then you would need several years to get you money invested back in heating savings, but you would eventually get your money invested back in savings only slower coming. Big savings will be the insulation being added sealing your house with the blanket of insulation in your attic. The initial R30 insulation added would be rapidly noticed both in heating cost savings and in level of comfort.

Just my opinion

Wg

[Tom L.]

I talked to the contractor today. He says R30 is much more popular then the 38. I was just wondering approx how many years it would take to get the investment back for up-ing to R38. They want an additional $110 for about 900 squre feet. (approx 13 cents per sqr foot). The furnace is a 12 year old 90% eff gas furnace that will probably be replaced in the next few years (its running good but having a few problems that are not directly effecting its output/effeciency).

RIght now we are penciled in for R30.

[Wgoodrich]

I pretty well felt that R 30 was best at first reading of your post. I suspect you will gain little savings with the extra depth of fiberglass insulation blown in considering the type home you discribed.

From where I live you have about a .5 increase in heating degree days in comparison. You should be fine in my opinion with the R 30

Good Luck

Wg