Product FAQ

The IsoDoor SD, IsoDoor HD, and IsoDoor V can be used in any situation. However, these doors do have different advantages that make them more suitable for specific projects.

IsoDoor V
Most often used in common walls that require more than the standard solid core or solid wood door. Hotels, home offices, and bedrooms commonly utilize this model. The IsoDoor V will keep up with walls that have resilient channel or MLV installed without losing performance. This sound dampening door is 1-3/4" thick, weighs 140 pounds at a standard size of 36" x 80", and performs great in walls up to STC 47.

IsoDoor SD
Most often used in offices, vocal booths, and other similar areas where privacy is of greater concern. This sound dampening door is 1-3/4" thick, weighs 240 pounds at a standard size of 36" x 80", and performs great in walls up to STC 55.

IsoDoor HD/HD LF
Most often used in home theaters, recording studios, and other areas to maintain high STC ratings. The door slab is 2-1/2″ thick and is supported with a continuous piano style hinge that runs the full height of the door. Despite the massive 340 pounds, the smooth operating hinge requires only 1/2 LB of operating force to open and close the door. The IsoDoor HD will provide great performance in any wall assembly with an STC rating of 62 or lower.

Another version of the IsoDoor HD is the IsoDoor HD LF. The specs on the HD LF are very similar to the HD, but the change in core design brings a considerable increase in low frequency isolation.

Communicating
We strongly recommend alternating the type of door when setting up communicating assemblies. Combining the IsoDoor SD with the IsoDoor HD or combining the IsoDoor HD with the IsoDoor HD LF will help avoid common resonance issues that occur when two similar materials are installed in the same assembly. Two IsoDoors can be used in the same communicating assembly with a slight change in core design to avoid these resonance issues.

Each door ships in a heavy duty crate to protect the door during transit. Up to four doors per crate to reduce shipping costs. Inside this crate you will find:

• Pre-hung smooth slab in jambs to match any wall depth.
• Full perimeter rubber seals, fully mortised automatic door bottom, hinges, and acoustic threshold.
• Slab bored for 2-3/4″ backset to fit standard handle, to be provided by the customer.
• Installation instructions, one year warranty.
• Endless phone or email support for installation and project planning.

These items can be customized to fit your requirements:

• Color of perimeter rubber seal
• Finish for the hinges and threshold
• Depth of the door jamb
• Door width (any width from 24" to 48")
• Door height (any height from 24" to 96")
• Backset
• Bore for deadbolt
• Custom wood finish for jamb and slab
• Double door up to 96″ wide
• Windows are available for each IsoDoor model in 5 different sizes
• Door handles and dead bolts available to match any decor through our IsoHardware.com site

Our standard door sizes are 36″ x 80″. Options are available for each door at 30", 32", 34", and 42" widths. Options are available for each door at 84" or 96" heights. Other custom sizes are available upon request ranging from 24" to 48" in width and 24" to 96" in height. Each door model is also available in a double door assembly (French doors).

Communicating doors install in the same wall back to back with anywhere from 3″ to 24″ between the doors. Our line of IsoDoor is unique in that we have full communicating door testing for any combination of IsoDoor style in several different assemblies.

The advantage of communicating doors is considerable. With doors installed back to back, a redundancy in seals and dead air space between extreme mass is created. This allows doors with single operable performance in the low to high STC 40’s to achieve ratings in the mid to high STC 60’s when communicating. This level of performance would not be possible in a single operating door.

The entire line of IsoDoor was tested in 2012 at NWAA Labs as single operable doors and in communicating door assemblies, with additional testing completed at multiple labs as recently as 2023. We have 15 official tests related to the IsoDoor line with performance ranging from STC 29 up to STC 65.

If a standard size door is purchased, then a lead time of about three weeks is typical for small orders with less than four doors. Lead times on larger orders are quoted at the time of purchase and range anywhere from four to eight weeks depending on the size and complexity of the order, as well as the location of the delivery.

Our manufacturing process is on a first come first serve basis. We suggest ordering as early as possible to be included in the manufacturing schedule and to avoid project delays.

The entire line of IsoDoor is backed up with a full one year warranty from the receiving date. Warranty information is emailed once the door ships. This information must be completed and returned to become valid.

Unfortunately, the accuracy and consistency of STC tests varies greatly from lab to lab and year to year. Many sound isolation door manufacturers have lab tests dating back to the 1960’s and 1970’s. The majority of testing we have found is no more recent than the mid-1990’s. To make it worse, many of the tests were done in the manufacturer’s own facilities in labs that cannot accurately measure the ranges tested.

Because of this, a competitor’s STC 52, unless tested recently, is not necessarily better than an STC 46 from us. Or a competitor’s STC 46 , unless tested recently, is very likely much worse than an STC 46 from us. The STC calculations are constantly changing and becoming more stringent, and new acoustics labs are more accurate than ever. We tested our line of IsoDoor in 2012 in an acoustic lab known as the most accurate lab in the United States. Our ratings may appear lower than some of the highest ratings you will find, but we are confident that our STC numbers will meet or exceed the competition and can be duplicated both in the lab and in the field.

We require payment up front for all orders. Payment can be made by check, credit card, ACH transfer, or PayPal.

They are very heavy, but the installation is pretty standard. The IsoDoor V weighs over 80 pounds more than a solid wood door, the IsoDoor SD weighs over 180 pounds more than a solid wood door, and the IsoDoor HD/HD LF weighs over 280 pounds more than a solid wood door.

The door arrives pre-hung in a jamb allowing a similar installation to that of a standard door. The only differences would be the adjusting of the automatic door bottom, which anyone can do with a screw driver, and the applying of the rubber perimeter seals, which again, anyone can do.

We are here to support the installers for as much as they need us. Installation instructions for the IsoDoor are available after purchasing. Each IsoDoor purchase comes with unlimited phone support for installation and other questions.

We are familiar with a few installers that have installed multiple IsoDoors. Typically we do not recommend installers to our customers. The best advice we can give for finding an installer is to hire a reputable finish carpenter. Finding one is as simple calling a local building supply store and asking for the names of a couple finish carpenters that are experienced.