Attic Insulation - Blown vs. Batt

Tim
Do you know what would be a better insulation, Insulite paper pulp insulation or cellulose blown in insulation. the ad I have says the insulite is blown in.
Thanks

Make sure whatever you use is UL approved and guarantees the least amount of settlement.

Why use batt at all and not a 2 part blown in polyurethane insulation. You end up with a closed cell, R7 per inch of seamless insulation? From what i read, the off gassing is minimal, and you don't need to inhale any fiberglass fibers in the process (our next asbestos). Plus, keeps mice from burrowing inside the blankets and keeps moisture out.... two things that diminish the effectiveness of fiberglass over time.

We recently had a new roof installed on our circa 1960 house. The roofer informed us that we would have to have vents installed in the exterior soffits otherwise the new roof's warranty would be invalid. We went along with this; however, I'm now wondering if our blown-in attic insulation was compromised in some way by the installation of the new vents. The vents were installed entirely from the outside; e.g., an opening was cut and a screen put into place. The workmanship was poor, by the way, leading me to question if the vents vs. attic insulation was done according to code. Thank you for any insight you can offer on this matter.

Kathie,
There is a very slim chance the insulation was compromised. The soffit venting should be continuous if possible. You can't have too much soffit and roof ventilation. If you want to hire real professionals on all future jobs, consider using the handy Bid Sheets I developed. There is a link to them in the navigation bar.

Question:
My attic currently has R19 insulation I plan to add additional R30 to it. The question is at times I need to access the attic, with the R30 added I may miss a rafter when walking thru, Is it defeating/beneficial
to add polystyrene 4x2x8 panels before the R30 insulation is added?

Thank you

my fear with adding the poly is that if you currently have a vapor barrier on the underside of the batt (r-19), then your potentially trapping moisture between the new boards of poly and the vapor barrier. i would stick with unfaced R30 and as the writer mentioned, running perp to the existing insul.

i personally am plagued with 5.5" ceiling joists on the second floor and have it filled with 6" batt (r19). this spring, im pulling it all out and filling the 5.5" with a spray in foam (either "tiger foam" or "handi foam") and get close to an r40 in the same space.

Duc,
Anything you add should help. Seal air leaks as well.

MF,
No vapor barrier in attics!

if your insulating the ceiling of your second floor, and your attic is unconditioned space, the dew point will most definately find itself in the batt insulation at some point and then you have a condensation issue. always a vapor barrier between hot and cold!!!sometimes the vapor barrier is integral with the product, ie with a closed cell product and hence not needed... but packing faced insulation on top of faced insulation will certainly trap moisture.

Hi Tim!- I have an uninsulated attic in my 1880's era house. Most of the attic was finished when the house was built, and it has really neat wood siding on the walls and ceiling of the 2 attic rooms. There's only a crawl space above this that could even be insulated, as you can't get behind the knee walls (solid nice old wood siding/paneling) The crawl space isn't the entire width of the house.

Is it even worth insulating the crawl space above the attic rooms, since it's not like I'm insulating the entire attic? I'm wondering about this because I don't want to waste money on something that's not going to have much return, and I've heard that I need to get the electric updated from "Knob and Tube" before any insulation gets installed.

Treje,
You can't insulate over knob and tube as that wiring was designed to dissipate heat in the air.
All conditioned rooms should be surrounded with insulation.

I currently have fiberglass blanket insulation. I was thinking of adding blown insulation over top of it? I am not sure what it is called but it looks like laundry lint. The bag says its natural and eco friendly, it's not fiberglass. Is this ok to do? Would I run the risk of developing mold, because it isn't blown fiberglass?

Mike,
It sounds like you are describing cellulose insulation. Keep it dry and you will not need to worry about mold.

We live in Tucson, AZ in a home that was built in the early 60's. It has no insulation in the roof! There is just a layer of foil next to the drywall ceiling. With this foil, will blown in insulation be effective? Also, after reading your column warning about not reducing circulation in the attic I'm concerned that blown-in insulation will fill the space too much and cause a problem with ventalation. There are round 1.5" holes on vertical wood under the eaves outside. Will blown-in insulation cover these holes and reduce the air circulation in the airspace. We have no attic or crawl space. Thanks! Cynthia

Cynthia,
So you have a flat roof with no access? If so, you have few options. If not flat, call three insulation companies and get some bids.

We are looking at buying a renovated house, originally built in the 50's. In the attic, the roof joists have insulation on the east-facing side only. Old looking batt insulation, perhaps "balsam wool". On the ceiling side (attic floor) is some thin insulation batt in some, but not all places and not the balsam wool type. What is the BEST thing to do here? Part of the attic has been floored. Some or no insulation under this. The seller is willing to take care of this, but I would like to know what to request.

The house does have turbine vents and gable vents up there, with a stairwell access.


Thanks
Randy

Randy,
You can add insulation to get to an R-49 and also investigate a radiant barrier product. Read all of my Insulation and Radiant Barrier columns.

We purchased a home only to discover that the prior owners had converted the attached garage into a master bedroom. They had insisted they were "fully permitted" when we purchased the house. We must now retractively permit the addition and bring it up to current code which includes bringing the cathedral ceiling insulation to R-30. The ceiling joists are only 2 x 6, and the insulation is only 5" of fiberglass batts. We had pretty much decided to remove the existing drywall, install 5" of rigid insulation and replace the drywall. Since the prior owners will be paying for all this, their consultant suggested we could leave the drywall and fiberglass insulation in place, drill multiple holes in the drywall and spray in a foam insulation. Everything I have read seems to suggest that spray-in foam is only used to fill open cavities and it seems like spaying foam into a closed space already filled with fiberglass bats would create uneven coverage where the fiberglass interrupts uniform coverage. Your thoughts?

Barrett,
Remove the drywall and do it right. Contact the different foam mfrs and see which ones can retrofit what you have to meet/exceed the code AND ensure there will be no venting issues.

I am getting estimates for blown-in insulation for an attic and floor space of a small house. The floor space is a trust system. One company suggests fiberglass and another would use cellulose. Assuming proper installation, is one better than another, especially considering the spacing within the trust system? Thanks.

MS,
R-value is R-value. Please read ALL of my Insulation columns and use that data to help guide this decision.

Can you install cellulose insulation over old nob and tube wiring?

GP,
No. You can build a box over the wires to create a 2-inch air space though and then add insulation over the box.

In a new house with a tray ceiling in the bedroom and a 8' X 14" plant shelf the architect's specs include "hand packing" the insulation around these areas. Now, the installer in the field, says that blowing the insulation in is more effective because the pockets of air trapped in the blown in fiberglass is better. which way will I have the most protection. we live in Wisconsin, and the winters here are very cold. Please reply tomorow if at all possible thank YOU very much. Ed.

Ed,
If that area can be successfully blown, do so.

New to this insulation thing.
Just measured and we have 5 1/2 inches of blown in chopped up papery stuff in the attic now. Your chart says we need a R of 7. How do I determine what my exhisting level is knowing that I have the 5 1/2 inches of blown in so I can figure out if I need more.Thanks for the help. NB

NB,
You need a table from the mfr of the product to determine its R-Value. I assume you might have cellulose.

Hi I'm currently renovating an old (1935) home, story and a half. I've got R-20 between the collar ties with R-40 prpdulr to that. It's the sloped areas I get different suggestions for. some guys say spray foam, (most expensive), 2" foam with blown in, or R-20 batts with venting(what I currently have). I also ran sill gasket foam on all rafters mostly for sound. My roofer says install a metal roof then I won't have to worry about the venting. Is this true?

The house I owned about 15 years ago we had the attic insulation blown in. It was a white ceramic that looked like cotton. I am not able to find anyone that has heard of what am talking about. The stuff was great because it didn't bother your skin when you touched it and it was fire proof. I think it was made by Owens Corning or 3M. Have you ever heard of this type of insulation?

CE,
In my opinion, that is bad advice. You can't have too much ventilation. Where will the water vapor go?

Van,
Yes, I have seen it.

I would like to use the blown in loose insulation as a sound barrier between first and second floors. Is this possible and would it deaden sounds between floors.
Thanks,
Jack

Jack,
It is possible. Will it work well? You better go read ALL of my past columns on Sound and Noise Control.

Tim,
I just purchased a home with a relatively new 'tear-off' roof and finished attic rooms but the owner did not add any replacement insulation and left some old insulation on the pitched part of the roof that looks like paper.

I plan on removing the old and adding fiberglass insulation on the roof, kneewalls and outerwalls. BUT that crawlspace under the roof behind the kneewalls has inplace floorboards as opposed to exposed joist. How should I go about insulating that floor, just lay it on top?

Ray

Ray,
That should work. Get opinions from a couple of professional installers. You might be shocked at the low price and a better idea.

I have just had a new roof installed over an apartment bldg I own. Heat gain is a problem in this bldg in Southern California. There are no soffit vents and the soffits are open beamed to the exterior with the stucco exterior walls continuing up in between the rafter tales. This made it extremely difficult to even attempt sawing through the stucco to install eave vents. Since there also were no roof vents I have installed low profile roof dormer vents at the rate of approx 1 sq ft of vent for every 150 sq ft of attic floor space, splitting the vents 50% evenly distributed on the top roof ridge and 50% at the lowest parts of the roof, evenly distributed to allow for even intake and exhale of the hot attic air. Now that you can picture what I have my questions will follow: The attic floor joists do not have any insulation and I'd like to find the best brand/type to have blown in. What do you recommend? If you have any other hints to properly keep the heat of the attic space from flowing into the bldg it would be appreciated.

Rich,
Fiberglass should work.

I'm trying to decide between blown in foam and rolled in recycled denim (blue jeans). I'm sheathing my house with plywood, Tyvek, rigid foam board, and siding. Someone said putting blown in foam behind this could possibly trap moisture in the plywood and cause rotting and/or mold. What are your thoughts?

DS,
Any insulation can trap water in a wall cavity. Your challenge is to ensure water vapor does not get into the wall.

Live in VA. Have blown-in fiberglass(approx. 12")in attic. Would like to add more in the form of batts. 1. Should it be placed over the blown-in stuff (compressing it)? 2. If not, should a vapor barrier be used? And, should the blown-in be saved and "raked" over the batts?

Regarding fiberglass insulation being blown in over open attic floor joists:

I have read that the EPA lists fiberglass as strongly suspected to be a carcinogen if inhaled. I have rental properties where I'd like to insulate the attic floor joists, but am concerened that "fiberglass" could be the next big lawsuit trend, such as asbestos, lead paint, and now mold. Since most attics have a crawl space at minimum, where people could climb into, doesn't it seem not worth the risk to use fiberglass? Bear in mind the courts usually rule agt the property owner, even if the tenant caused the problem by climbing up there. Do you agree with me or have other things you can add?

What exactly is blown-in insulation? My husband is renovating a house, but I was just wondering.

I live in Florida and have bought a late 1970's block home as a fix r upper. It has the original insulation it the attic, in good shape. It is a single layer of Manville fiberglass about four inches thick, no R value printed on the paper face. I have added two gable vent fans and I am in the process of pulling the existing batts out of the soffit so the attic will breathe and re-taping and applying mastic to the a/c ducting. I would like to add additional insulation over the existing and would like to know if either glass or cellulose can be blown over the exixting insulation?

I have just bought a home that was probably build in the 40's or 50's. There is no insulation in the attic and the wires are run on top of the joists. I am considering blown in insulation and am concerned about the risk of fire if I blown in the insulation on top of the wires. Is that a valid concern and what kind of insulation should I use?

Tim,we have a new house about a year old. The attic has blown in insulation except above the garage they left that bare. Anyway my buddy is remodeling a 60,000 square foot store the existing R-19 2x4 batt insulation is to be given away, it is clean and fluffy.I intend to get enough to cover my garage but it is FREE how much is to much. I thought about insulating between the rafters up to the bottom of the decking but don't know if that will cause ventilation or condensation problems. I can get enough to stuff the whole attic. Can to much cause problems.

I live in a manufactured home in Florida, and I just had some blown-in fiberglass insulation added to the attic space in my home. Since there is no access to the attic from inside my home, the installer said he installed the insulation thru the 4' roof vent.
Is this possible? Also, there is no way for me to see how much he installed. (he said R-19)
I don't see any difference in my ac bills, and I'm wondering if I have been "ripped off" ????????????
Something doesn't sound right to me and I am very suspicious, how can I
check?
Please respond to my email address ASAP, because time is a factor.
Thank you, J

have a 720 sq.ft grage space gutted at the moment and wanted to know what the best insulation was to put in there. batts vs. blown in i live in central mn.

i have raked ceilings. can you please tell me if it is worth installing insulation? i have been told that cellulose may be good for this.

Hi, I own a small single story flat roof house built in the late 40s. Cinderblock walls - no insulation most likely. I replaced the roof a few years ago and added insulation. The ceiling has old insulation that looks like balsam. So now I have a vented attic space (approx 5 inches). My question is should these vents be closed off? I was told to use stucco like the rest of the house. This would turn the attic into "dead space". Would this help make the house more effecient for heat and cold?

I want to add some more blown-in insulation in my attic before installing a radiant barrier. Rether than deal with the dust, can I just buy the bags and spread the insulation myself. I want to avoid all of the airborne particle as I am also putting a bubble wrap/foil barrier over the ductwork.

Thanks,

I have a house that is 16 years old with original batt insulation in my attic. The house is hot in the summer and cold in the winter and would like to have the insulation checked and updated if needed. We have a whole house fan installed in the hallway. If we want to have blown in insulation added could it cause problems when we turn on the whole house fan by dislodging and covering the vents?

What are the pros and cons of fiberglass insulation versus cellulose recycled plastic pieces? One company said rats like to next in fiberglass, but not in cellulose. Which do you recommend and why?

WE HAVE A WHITE COTTEN LIKE ATTIC INSULATION THAT I ASSUME WAS BLOWN IN. OCCASIONALLY SMALL PIECES THE SIZE OF COTTEN BALLS FALL THROUGH AN ATTICE FAN I INSTALLED IN THE CLOSET. MY WIFE IS FEARFUL THESE ARE A SOURCE OF CONTAMINATION AND HARMFUL TO HER HEALTH. I THINK IT IS A FORM OF CELLULOSE INSULATION TRATED WITH A FIRE RETARDENT. IT IS A WHITE AS COTTEN BALLS. IS THERE CAUSE FOR A HEALTH CONCERN?

I currently have 6" batts in my attic. I'm looking at adding blown insulation. I have 2 offers. The first adds 15 inches to my already 6 inches making what they say would be an R64. The other adds 6 inches to my 6" batts. They say their 6 inches makes an R19. Adding to my batts I assune makes this an R38. Which is my best option? I live in Maine.

Thanks for all the tips...definitely things to consider before winter comes

Why can't I install Blown Insultation by simply dropping it into place, inside the attic? My time is free, and I can take the time to do it correctly and wear proper facemask for protection from fiberglass. Is it available for purchase by a typical residential customer? I don't like the batt insulation option of cutting and installing in precise manner. I also don't like the cellulose wood product that appears to be made of old newspapers ground up. Your help would be greatly appreciated.

I have a an old house (1920s) with very old, scant, dirty looking insulation in the attic. Should I remove and replace or can I install some new insulation over it?

I'm adding insulation to the attic of a ranch house. The only insulation was done with the fiberglass facing up to the roof. Do I need to remove the old first? If not, do I install new with fiberglass facing down?

Indian Harbour Beach, FL - During Tropical Storm Fay, the rain was blown up and under our single story roofline ridge vent. There are several areas where the ceiling plasterboard is now damp (especially at the seams), the paint has bubbled and cracked, and some brown water stains are also starting to appear in the ceiling paint.

What I am most concerend about is mold growing in the attic. The blown-in insulation in the attic is damp directly under the vent where the water was blown in due to the rain coming down sideways. I left the attic access panel open to allow air to circulate better, which I hope does not feed the mold growth in the attic.

Is there anything I can do to remove the dampness from the insulation - (DampRid) or will the insulation eventually dry out on its own?

Should I have the insulation professionally removed along with the wet plasterboard, or just wait for it to dry out, prime with Kilz and pait over the water stains?

Thanks for any professional suggestions,

Julie E.

Any

Texas summers have gotten to our energy bill. Our AC is constantly running. We've found also that radiant barriers are very effective for saving energy. These guys-www.stophighenergybills.com do spray on radiant barrier on the inside of your roof. It works pretty good for us.

I have blown-in insulation in my attic. During summer and winter when the a/c and heater are in operation, every few days I see a fine white dust all over my furniture, window slats, bathroom sinks. What is causing this and how to get rid of the problem? I am afraid I may be inhaling the white dust. Is it from the blown-in insulation?

What part of the country did you find a contractor to blow in the attic insulation for 40 cents per square foot? I have been canvassing the east bay area and its a minimum of $1 per square foot and upwards to $2 per square foot. I have an 1800 square foot house and am looking for a contractor to bring my insulation up to R38 or better. All that is up there now is the batting in between the 2x6's.

I have some tube and knob wiring btwn. joists in my attic floor (much was removed but some we can't get out w/o ripping walls apart). I laid fiberglass batting insulation where the wiring was removed but don't know how to insulate where the wiring still is. There's not enough room to build a 2" box around it...is it possible that I just can't insulate a significant part of my attic floor?! I've considered glueing cut-to-fit pieces of poly panels to the underside of the plywood flooring I'm laying down as a solution of sorts. Thanks for any advice.

I want to add an additional R30 of value to my attic. I have about R20 from what I can estimate (1950s house in New Hamphsire and winter temps can reach -20F or so). Thee baffles I've seen others use seem appropriate for eaves without a continuous venting. My eaves have continous vent across the 50 foot span. What do you recommend? Also, I've seen that Home Depot rents the blow in equipment and while I'm not yet sure of batt vs. blow in, if I choose blow in - I wondering if it is a reasonable job for a home owner.

I have blown in insulation in my attic can I put batt on top of this or do I need a moister barrier if so what kind.

Has anyone done a thorough analysis of radiant barrier paint vs. techshield or similar product? Thanks to Ike, I have the golden opportunity to take off the (rest of ) existing deck and replace it, or have it coated, but don't know which would get me the most benefit.

I have Nu-Wool blown in my attic to a depth of 15in. After nine years it has settled to about 7-8inches. Have I lost some of the insulating value? If so can I blow in more insulation on top of the old? I was thinking of using the Owens-Corning product that is pink soft material and easy to install. Thanks Paul

We are interested in adding blown insultation to our attic on top of batt insulation. As we have an attic fan, which vents into the attic, we are concerned about the blown insultation being blown around. Since vapor barriers are not used in attics, we were wondering about tacking down a geotextile fabric. Would this cause moisture problems?

I have two questions:
1) We have a 30 y.o. 2800 sq. ft. one-story home in New England. The attic has original blown-in insulation, and, at the very outside end of each joist space, there is a small rectangle (10 H X width of joist) of fiberglass batting. This was placed there (I think) to prevent blown-in cellulose from entering the soffit area.
I purchased styrofoam vent chutes and am knocking down the little barriers (that isolate the soffit area) and have slid the vents down into the soffits...then am pushing the insulation back up against the vent to hold it in place against the roof. This allows the full length of roof to be exposed above insulation, including the soffit area that used to be separated. Was this the correct thing to do?
2). After installing the vent chutes, I am laying R-35 unfaced fiberglass batting perpendicular to the floor joists, covering the cellulose, to improve insulation. However, I scraped to the bottem of the fluffy layer of cellulose and there seems to be no moiture vapor barrier. In the 20 yrs. we've lived here, we have had no moisture issues. Should I go ahead and continue to lay the fiberglass rolls? The attic is HUGE and I am patient... but not patient enough to figure out a way to take up all the cellulose and put down a vapor barrier!
All I want to do is max out our insulation without creating any future problems.
Thanks
maureen

I HAVE 2X4 WALLS .THERE IS THREE AND ONE HALF INCH FIBERGLASS INSULATION WITH PAPER BACKED VAPOR BARRIER ON IT. CAN I ADD ONE INCH 4X8 POLYISANUATE IN SULATION BOARD OVER IT TO GAIN AN R19

Question:
I am adding cellulose to my attic which already has 3-4"of fiberglass. I checked the and I don't have any soffit vents only two gable vents. When I go to insulate do I blow the cellulose all the way to the roof where it meet the ceiling rafters? I saw a lot about adding baffles above the soffits, but since I don't have any vents there I'm assuming I don't need to do that. Also, will having just two gable vents provide adequate ventilation for an 800 sft? Thanks for the help.

Hello,


I have a cape code home with a finished attic. I moved in to find attic mold because of improper insulation and plastic vapor barrier in place. The attic is finished and I wanted to know if I should use faced or unfaced insulation for the walls that are exposed to the cold air. On the top of the finished attic, I am going to blow in insulation; however, I was unsure what to use for the knee wall and floor below the knee wall. Also, my attic area goes out to the front porch. Should I insulate the porch area or just around the finished attic area? There are also two bedrooms over the garage, and they get very cold. I want to add new insulation under the floors in the garage roof. Should I use batts with the vapor face facing the bedroom floor?

Thank you,

I currently have blown in insulation and have a serious heat lose problem in my 1st floor master bedroom. I am considering installing batt insulation in addition to the blown in. Can i put it over top the blown insulation or should I remove the blown in and then place over top of the batt?
My home is 6 years old (the work should have been done to code).

I currently have 10 inches of blown insulation in my walk up attic. The joist are 2x8 so the insulation is pile above the joists. I want to put in a solid floor but I'm afraid that compacting the blown-in to 7 1/2" will hurt my R-value - adding 4 inches to the joists is one was (time consuming and costly) - with 10 inches of blown in I estimate the R-Value at 28. Cmpressing to 7 1/2 the the R-Value at 21. Can I add R13 batting on to of the blown in the apply the flooring (at this point I guessing the blown in will be at 6" (16.8 R) the the batting (13 R) = 31.8 R value

Hi Tim,
Thanks for all of your wonderful resources & advice. In reading "Insulation 101", etc. w/regard to my mother's poorly [batt]insulated crawlspace attic (above 1961 ranch house on slab), I'm still torn between products. A batt guy said access is too limited & they won't be able to effectively reach all spaces w/out coming through ceiling & rec'd I call a blower.
I want to be green, but cellulose doesn't have me sold (concerns about moisture/mold allergies if not properly installed & flammability).
Fiberglas has me concerned w/my history of asthma. In the next couple years, we will have to cut out patches of ceiling to reinforce above to prevent recurrent ceiling cracks. Airborne fiberglas in living area is not the look I'm after.
Also wonder how [inactive] AC vents are affected by blown in?
What do you suggest?
Many thanks!

I recently became the owner of a circa-1950s adobe/block/stucco house, with 75% of the floors slab/saltillo tile. Previous owners had put in central heat with ceiling ducts. The house is a heat-sink; central heat does very little to warm it. My sense is that a radiant heat-source would work best. The roof is an old flat one covered with a pitched roof; I want to insulate the roof/ceiling, but am not sure whether it would help any, over the old flat roof. What sort of insulation would work the best? I do love the Green idea, but does cellulose lose loft over time? (Get saggy, like most of us?) Also, could you give any important points to consider in choosing an appropriate heat-source? I've spoken with several natives of this area - Albuquerque, NM- about this sort of house and how to heat it, and so far it sounds like wood stove or pellet stove. Many thanks!

I am looking to upgrade insulation in my attic. The existing insulation is blown in approx 10 to 12" just covering the ceiling joists. There is no vapor barrier between the heated space and the unheated attic space. Am I better off with additional blown in or unfaced batts?

Hi, my mother in laws'landlord recently insulated the attic in her apt. with cellulose, she has a breathing problem and since the job was done she has not been feeling very well. Is there a possibility that this insulation could be affecting her health please tell me if so she has an upset stomach in the liver area and has become scared and concern. She is 75 years old and lives alone. Her son and I need to know what to do for her her health is not so good please help asap

Any experience with, or position on the radiant barrier approach to insulating your attic? I've been researching a company called "Eagle Shield" www.eagleshield.com and am looking to see if there is empirical data that supports the installation of their "NASA patented radiant barrier". Looks a lot like a layer of aluminum foil.

Thoughts on any increased ability to trap both hot and cold air underneath this blanket within your living space in the home? Their offer is to blow in fiberglass insulation and then cover with the radiant barrier for $2.00 per sq ft.

I have an old beach house in Southern California (Laguna Beach) with no insulation at all. I was considering placing fiberglass insulation in my ceiling and attached to the floor under the house to help hold the heat in (no A/C needed). My question is do you think this will help dramatically in keeping the house warm without placing any insulation into the walls? What about under the house attached to the floor? My house has vents that allow the cold air to flow underneath the home (cold air just sits there) so I thought it would be a good idea to staple the insulation underneath as well...what do you think? Basically I'm just wondering what kind of results I would get with holding the heat in with an insulated ceiling and floor and no walls?

I have about 900SF of attic and the same for the floor below and was wondering what I should expect to pay per SF and whar R level I should buy?

Thanks!
Dave