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Find Insulation pros in Portola Valley

Bay Valley Insulation Inc
4.7(
46
)

Serving Portola Valley, CA and surrounding areas

Approved

In business since 1988

Free estimates

Warranties offered

"We needed retrofit wall insulation and after checking around all the listings through AngiesList, Yelp, and others, we found that only Bay Valley and SDI does retrofit wall insulation work. We went with Bay Valley because the price was reasonable and they responded quickly and promptly (can't say this about SDI*). Joel was our estimator and he came out promptly at the time and date indicated. He was thorough and thoughtful on how he approached the job, not overselling or recommending things we didn't need. We live in an older house and he appreciated the home and looked for the most non-invasive method to take care of our un-insulated exterior walls. Bay Valley's approach is to come in from the exterior walls with the typical 2-hole process (high/low) to blow in the cellulose insulation. They sent two guys in and despite a couple snags in the job, they finished the job in one full day. Afterwards, they plugged the holes, textured and primed, and the next day came in to paint (our-supplied) paint. I was really amazed how well and seamless it all looked afterwards. They did a good job cleaning and even moved the cabinets in the garage back where they originally were. The real result? The mornings have been a little bit warmer than last week, but so far the heater has barely turned on over the past couple days. The house already feels warmed and less temperature fluctuations. We already got brand-new attic insulation last Fall, but the wall insulation really did the trick. A definite recommend to anyone who needs a good team to do insulation in their home. * dealing with SDI was a nightmare, unfortunately. With *several* calls about being in the ER, then lots of other excuses, it just didn't seem like they wanted to do the job or something. I originally made the request in August and this morning on Nov 10, I got a phone call inquiring if we still needed insulation done. sigh."
Additional Photos
1 neighbors recently requested a quote
Recommended by93%of homeowners
Bay Valley Insulation, Inc.
4.6(
192
)

Serving Portola Valley, CA and surrounding areas

Approved

In business since 1988

Free estimates

Warranties offered

"I hired Bay Valley to clean out one attic and blow in insulation to the two attics in my home. Joel came out and did a thorough inspection, explaining everything as he went along. the quote was reasonable and fair. Unfortunately, on the scheduled day the team was overbooked and although I had taken the day off, by the afternoon it was clear they would not have time to do my job. Knowing I was disappointed , they agreed to come the next day, which was Saturday even though they don't work Saturdays. Tony and Henry arrived in the afternoon and worked literally non-stop for hours until they got the job done. They were as clean as such a job allows for and when they left the debris was gone. I would recommend Bay Valley Insulation to anyone but I would also be sure everyone was in sync on the schedule."
Response time1 day
66 neighbors recently requested a quote
Recommended by99%of homeowners
Avatar for Eagle Shield
Eagle Shield
4.3(
18
)

Serving Portola Valley, CA and surrounding areas

Approved

In business since 2003

Free estimates

Emergency services offered

"I love this company! Garrett came to my home and assessed how efficient our current insulation, etc was. He was very informative and friendly — explained what we needed and how they could help. At the time, I decided to hold off and he never pushed the sale. When I was ready, he was quick to accommodate my schedule. His team: Angel, Luis, Tommy and TJ were great! They arrived early, were professional, courteous, kind, very helpful with my questions and were above and beyond to help fix things that I wasn’t even aware of. They also were more than happy to help with small problems that I had no idea how to fix. They worked quickly and cleaned up afterwards. You could tell they cared about their work which makes me feel confident that the job was done right. They were also fun to have around — my Great Dane loved them too! Garrett and Dave checked in with me during and afterwards to make sure things were going well and if I had any questions. I highly recommend Eagle Shield."
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+9

Response time7 hrs
1 neighbors recently requested a quote
Recommended by84%of homeowners
Avatar for Attic Pros
Attic Pros
4.9(
233
)

Serving Portola Valley, CA and surrounding areas

Approved

Super Service Award Winner

In business since 2012

Free estimates

Credit card accepted

"I was looking online for insulation contractors, and found Attic Pros, Chris and his team arrived on time installed brand new attic insulation, cleaned our Crawl space and installed insulation, they took photos before and after. I am very happy with the work was completed defiantly recommend these guys."
Blow-In Attic Insulation
San Jose, CA Attic Insulation Installation
Danville, CA Vapor Barrier Installation
Mill Valley, CA Crawlspace Cleaning
Benicia, CA Attic Cleaning & Insulation

+3137

Response time11 hrs
Response rate94%
137 neighbors recently requested a quote
Avatar for Atticare Construction
Atticare Construction
4.5(
172
)

Serving Portola Valley, CA and surrounding areas

Approved

In business since 2008

Free estimates

Warranties offered

"The crew arrived on time and installed plastic on the floor and walls for protection. They did a good job removing the old insulation and installing new insulation. The crew did a great job cleaning up. Nice professional job."
Before Atticare Services
After Properly Sealing the Access
After Insulation Installation
Clean and ready for Insulation Installation
After Insulation Installation

+26

Response time2 hrs
Response rate91%
4 neighbors recently requested a quote
Avatar for Insulation Alliance
Insulation Alliance
5.0(
26
)

Serving Portola Valley, CA and surrounding areas

Approved

In business since 2017

Free estimates

Emergency services offered

"Attic Professionals was awesome to work with and highly recommend their business for anyone looking for attic work. We hired his business to replace the insulation in our attic after I took care of a rat issue. We needed all the insulation and droppings removed, cleanse, and replace. Attic Professional crew were diligent with making sure the interior of our home was protected covering the walls and floors to remove the old insulation and did a great job installing the new insulation. Thank you for great service!!!!!!!!"
Soundproofing
Soundproofing
Attic Cleaning
Attic Cleaning
Attic Cleaning

+103

Response time2 days
Response rate93%
22 neighbors recently requested a quote
Avatar for SDI Insulation, Inc.
SDI Insulation, Inc.
4.1(
55
)

Serving Portola Valley, CA and surrounding areas

Approved

In business since 1975

Free estimates

Warranties offered

"Joe Stromberg, project manager, is an excellent asset of the company!!! I was also lucky to have two skillful workers who performed the project. I will definitely recommend SDI Insulation if asked to. Luba"
Spray Foam Insulation
Cooton Batts Insulation
Fireplace Sales and Install
Interior Insulation
Interior Insulation

+22

Response time2 days
30 neighbors recently requested a quote
Recommended by100%of homeowners
Avatar for AtticElite Insulation Solutions
AtticElite Insulation Solutions
4.6(
27
)

Serving Portola Valley, CA and surrounding areas

Approved

In business since 1999

Free estimates

Warranties offered

"I actually had both my attic and walls insulated. Great price, on-time, efficient, clean-up and communication. Unusual from most contractors today. I would highly recommend these guys. Milo was our contact."
Get $500 Off Rodent Proofing
Get $500 off crawl space cleanup.
Get $500 off rodent proofing.
Spray Foam Insulation
Before Attic Clean Up

+77

Response time2 days
69 neighbors recently requested a quote
Recommended by73%of homeowners
Avatar for American Attics
American Attics
5.0(
8
)

Serving Portola Valley, CA and surrounding areas

Approved

Free estimates

Emergency services offered

Warranties offered

"American Attic was everything they promised. Met with the owner , Sam, within a day to get a quote for removal of old insulation, rodent control and install of new insulation. He was professional and explained everything in detail of what was work was going to be done and how long it would take. We scheduled within a week at a reasonable price. His crew were neat, organized and finished on time! We were notified of some extra things that were found while they were on the job but were not pressured to have those things done. We recommend American Attic to friends or family and would definitely use them again."
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Additional Photos

+52

Response time2 days
5 neighbors recently requested a quote
Recommended by37%of homeowners
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FAQs for insulation service projects in Portola Valley, CA

Old insulation should be removed when it shows damage, contamination, or heavy deterioration. If you notice water stains, rodent droppings, mold, or large gaps, plan on taking it out to protect your home’s energy performance and indoor air quality. Removing compromised material eliminates health hazards, cuts energy loss, and sets the stage for a safer, more efficient attic—all while keeping utility bills in check.

R-value measures how well insulation resists heat flow—the higher the number, the better it slows heat transfer. The right R-value keeps your home warmer in winter and cooler in summer, saving energy year-round. Match the rating to your climate zone and have a pro verify performance over time, because moisture or settling can lower R-value and cut efficiency.

Attic insulation can stay in place for 80 to 100 years, but its performance often drops after the first 15. As dust, moisture, or mold build up, the material loses R-value and allows heat to escape. Schedule periodic inspections so a pro can tell you when replacement makes sense—helping you keep energy bills down and indoor comfort up.

You can over-insulate an attic. Beyond the recommended R-value, extra layers don’t add efficiency and can trap moisture, leading to mold or reduced performance. A local insulation pro can measure current levels, confirm the right target for your climate, and advise on any adjustments so you avoid future energy or maintenance headaches.

Insulation can be damaged by mold, pests, water leaks, or accidental electrical contact. When the material is compromised, it loses R-value and can introduce health hazards. Removing and replacing affected sections restores efficiency, while routine inspections from a qualified pro help you catch problems early and keep your attic safe and energy-smart.

The Portola Valley, CA homeowners’ guide to insulation services

From average costs to expert advice, get all the answers you need to get your job done.

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