Calculating Blown In Insulation Cost

With ever more focus on energy efficiency in the home, insulation is one area where the average home can make a significant difference. Whether your reasons are financial, environmental or purely for comfort, blown in insulation will go a very long way to achieve those goals. On this site we will guide you through the planning process and advise you on how much insulating material will be required to get your project completed.

For most people the main question will be about the blown in insulation cost and this site will provide you with a guide to estimating those costs. Also keep in mind that you can claim a Federal Energy Efficiency Tax Credit up to $500, which can go a long way towards paying for the job.

The most commonly used material for the blow-in method is fiberglass, so the first table will focus on this material. Ultimately, the cost will come down to the amount of insulation you want to have blown in. The more insulated you want your home to be, the more material will be needed, and the more labor time will be required to get the job done.

Blown-In Attic Insulation Costs:

​The following chart will serve as a blown in insulating calculator that will also help you plan the job by giving you a good indication of the depth and time involved.

R-Value Bags* Per 1,000 Sq. Ft. Material Cost** Installed Thickness Inches Hours of Labor***
R 30 15 $495 10.25 4
R-38 20 $660 13 5
R-44 23 $759 14.75 6
R-49 26 $858 16.5 7
R-60 32 $1,056 20 8

* based on average bag weight of 28.5 lbs.

** Based on Home Depot price of $33 per bag

*** this is dependent on the machinery used

[easyazon-block align="left" asin="B001B158EK" locale="us"]

R-30 is the minimum recommended amount for attics, in order to achieve more thermal efficiency. At a current price at Home Depot of about $33 per bag, the material costs will be a minimum of $495, plus 4 hours of labor. Blowing material into an attic is a relatively straightforward DIY attic insulation job. All you will have to do is rent the machine and get one other person to help you out by keeping the machine filled.

So for a DIY job on a 1,000 sq. ft. attic you can expect to pay:

  • Materials: $500 to $1,100
  • Machine rental: $100
  • Total: $600 to $1,200

While this is a rough blown in insulation calculator it will prove pretty accurate, and the great thing is that you can add more material at a later stage if your budget is limited.

Check out our recommended local Insulation Specialists:
Spray Foam Insulation Dallas

Continue reading

DIY Spray Foam Insulation Cost And Equipment Kits

While blown in attic insulation using materials like fiberglass and cellulose is by far the most common we have encountered ever better products like DYI spray foam insulation kits. In this article we want to outline what it involves, how it works, what the benefits are and how much it will cost. We should note at this stage that if you have already blown insulating material into your attic then spray foan is probably not a viable addition you should look into.

The reason for this is that in an attic space the foam needs to be sprayed directly onto the ceiling boards of the room underneath. This means that you need to remove any flooring and existing material. If you have insulating bats then this is a lot easier than the loose blown materials, which can be very messy and time consuming. If your blown cellulose of fibreglass is old and not very think then this may well be a good time to consider switching to a spray foam insulator.

General Improvements

The main benefit of using spray foam insulation in an attic space is that it provides an airtight seal and stops any kind of airflow. This increases your level of thermal barrier and also stops any damp and moisture build up which can be harmful as it can be a cause of mold. It also reduces the amount of allergens that float around your house, which is especially important if you have anyone in the household suffering from allergies to airborne materials.

Even the smallest cracks and gaps in the building structure can be fully sealed with foam. This is mainly because when the foam is pumped out through the nozzle it is still in a very liquid form. As the liquid dries it expands in all directions, thereby filling gaps and small spaces.

Fire Safety

A well planned and applied spray foam layer will also act as a fire retardant making it a lot more difficult for fire to spread into an attic space. Especially in places where there is easy airflow, tiny sparks can easily spread an cause a very rapid spread of fire.

While practically all spray foam materials these days are fire resistant it is very important to make sure you double check that before committing to a specific brand or service provider. Non fire resistant foam materials can in certain circumstances actually enhance the spread of a fire or be the source of a fire in the first place.


spray foam insulationBecause spray foam comes in many different materials it is very difficult to come up with one single spray foam insulation cost calculator. One thing we have to highlight first though. A lot of foam material used by contractors is quite toxic at the time that it is sprayed and still air born. This makes it less than an optimal solution as you would have to pay someone to do the job and vacate your home for several days.

One great product we have found is called Foam It Green which only requires a mask while the foam is being sprayed on. The spray foam equipment that they provide is practically fool proof and requires no experience at all. And also, the foam they sell will provide up to R-7 value per inch! That is an incredible amount but it does come at a price.

Combination With Blown Types

What we have worked out is that one of the best solutions you can come up with is to combine spray foam with the blow-in method into one project. This makes an attic airtight and very well insulated. Our cost calculation for this exercise will assume a standard attic space of 1000 square foot and that you are only planning to insulate the floor.

The home kit from Foam It Green covers a space of 1,200 square foot and includes the material, hose and gun including several nozzles and many extras that are very helpful. The price for this kit is $1,500, which is quite a bit more than the average blown insulation project. But we have already mentioned the benefits of doing this.

The great thing is that Foam It Green offers different packages that let you order just as much as you need. The cheapest way to cover 1,000 sqf is order two of their 602 packages, which will come in at just about $1,250.


Another advantage is that 1 inch of foam insulating material will provide R-7 value levels, which means that you can save a bit of money because you will not need as much bat or blown insulating material on top of that. Our best estimate for combining spray foam cost and blown types is that it will be coming in at $2,000 for both given a 1,000 square foot attic space. But savings from a proper attic project can be very significant whether you are heating or cooling your house.

Unlike blown insulation material, spray foam will stay exactly where you point the nozzle. This does mean you have to be sure that you are pointing in the right direction. Once it hardens it will not easily come away.

From a time investment point of view we would say that you should probably allow for 10 hours of work to prepare the attic, spray the foam and blow in fibreglass. It is probably best to do this over two days as it can be a very tiring job and being stuck behind a dust mask can become uncomfortable over time.


There are some disadvantages that we have encountered where people complained that they did not get the expected results. In the vast majority of cases this is due to the fact that either (a) not enough foam thickness was applied or (b) heat and air leakage spots were missed during the application process.

The first issue can be easily remedied by proper planning. The foam kits we recommend above will indicate the amount of space they will cover. If you finish you job and have some material left then somewhere you did not apply enough foam. One trick is spend a little bit of extra time planning.

When preparing your attic you use a thick marker or spray paint to make regular markings on the attic joists to indicate the exact depth you want to achieve. This way you can see exactly how high the foam is reaching. You can also use a needle to prove the thickness in regular intervals to ensure you are not applying it too thin.

Making sure that you do not miss certain cold spots is a bit more difficult. There are many very tight and difficult to access spaces where you will almost be guessing whether you have properly applied the material. We would always suggest identifying those areas during preparation and to start there, as it will allow you to build up a little extra material. Also, once you are finished with the project spend a little bit of time in the attic, ideally on a windy day to see and feel if you notice any obvious drafts.

Other Benefits

For the best possible results we would highly recommend the dual approach to insulating your attic. Spray foam is a really easy to handle material as long as it is made of low toxic materials when air born. With the majority of thermal exchange and loss happening vertically this is the one area where a little extra investment will go a long way. Once you factor in the ability to offset the cost against your federal income tax bill you will have already reduced the overall project cost quite significantly.

With energy savings on an average house estimated at $40 to $60 per month, such a project will have paid for itself within 3 years, so it really should be an easy decision to make. The work involved is simple and requires no hiring of expensive contractors. It also takes little time, saves money and adds huge amounts of comfort as well.

You should also take into consideration that a well insulated house will significantly add to the value of your house. If you talk to any real estate agent they will confirm that insulation and energy efficiency have become a significant selling point. At the same time, many home buyers do not want to buy a house and then have to plan for DIY jobs like this. Being able to provide this benefit will be a good selling point.

Save Valuable Energy With DIY Attic Project

With ever increasing energy costs and parts of the country seeing some extreme weather conditions in recent years it is no surprise that more and more people are looking to reduce their bills and live in a more environmentally friendly way. For a long time insulating projects were very costly and would generally require the expertise of a professional installer. However, with advances in materials DIY attic insulation jobs are now quite simple and straightforward.

The attic space of any building is probably one of the easiest and cheapest areas for temperature insulating materials to be installed. While windows and doors are commonly where most temperature exchange takes place, it can be very expensive, time consuming and disruptive to replace old inefficient windows. With improved levels of attic thermal barriers you can improve your energy footprint and the general comfort level quite significantly.


Blown Insulating Material

The great thing about blown materials is that you can quite easily get a very even spread of the material even into the smallest corners of your attic. Mostly made of fiberglass or eco-friendly cellulose or other recycled material, it is fed into a blowing machine and then pumped through a hose. All you need to do is point the hose in the direction you want the material to go. It really couldn’t be simpler from a DIY perspective.

DIY Attic Insulation

DIY Attic Projects

What you need to do first though is calculate how much insulation you want to achieve a certain R-value and then work out how many bags of material you will need. Blowing machines can be rented from places like HomeDepot and with the help of one extra person you can have your attic insulated in less than a day.


Rolled Bats

This type of insulation is practical and relatively easy to apply as well, but it does require a bit more manual labor. Mostly made of fiberglass these rolls come in varying widths and lengths. Your job involves cutting the rolls so that they fit between attic joists and this is where the job does become a bit more time consuming. Especially around difficult to reach areas of your attic it can be quite complicated to get the material tightly installed. However, it can end up costing you less as you do not need to buy or hire insulation blowing equipment.


Foil Backed

Another easy way of DIY attic insulation is to use foil backed insulators. Essentially this material is supplied with a foam or fiberglass center and a heat repelling foil on each side. Similar to the above rolls you will be required to cut these to size. As the insulator comes in a more rigid form it does make it a little bit easier to apply in certain areas, but it is definitely not as good as the above two solutions.



DIY attic projects really has become quite easy and even someone with very limited home improvement skills will be able to take on such a project with a little bit of planning and calculation. Blown insulation will definitely provide the highest level of benefits and save the most amount of energy with very little effort. Best thing to do is check out how much material you would need to achieve a certain R-value and then work out whether renting a fibreglass/cellulose blower adds a lot to the costs. In many cases it really is worth it, as the job is much tidier and less time consuming. But make sure you don’t just stop after one insulation project, there are additional Home Insulation Tips And Energy Saving Ideas.

Some Useful Home Insulation Tips And Energy Saving Ideas

There are many things you can do to make add insulation to your home. Some are smaller projects, while others will take considerable time and effort to plan and execute. But here are some home improvement tips and energy saving ideas to consider.

1) Insulate hot water and heating pipes

Especially if you are living in an older house you should check if hot water and heating pipes are insulated. This is particularly important if the pipes run along un-insulated cavities or in an attic space.

As long as all the pipes are not hidden in walls this can be a relatively straightforward job to do. DYI stores like Home Depot can provide you with foam insulation. This comes in different lengths and diameters, so you need to know how thick the pipes are.

Pipe Insulation Once you have the right insulation it is simply a job of wrapping it around any exposed and easily accessible piping. This can make a very big difference to your heating system, as heat is not lost in spaces where it is not needed.


2) Double or triple glazing

Windows is where houses lose most of their heat. Double glazing has been very common for many decades and is certainly a huge improvement on single glazing. However, these days you can get triple glazing which reduces heat exchange between the inside and outside of a building.

This certainly is a big and expensive project to undertake. If you have an old house with single glazing, then this is a hugely advisable thing to do. As mentioned already, most heat exchange takes part through windows. Before yo make a final decision you are probably best off hiring a specialist.


3) Service heating boiler regularly

Strictly speaking this is not an insulation tip, but it is something that will greatly improve the efficiency of your hot water and heating system. Just like cars, hot water boilers have to be serviced regularly.

If this is done at least every 2 years then your boiler may start performing worse than it should. This will result in more fuel use to achieve the same output.


4) Replace an open fireplace with a solid fuel stove

home insulation tips  Everyone enjoys an open fire in the winter; there is something very comforting about it. But, up to 70% of the generated heat will escape through the chimney. That is a huge waste and the heat would be much better used if were to stay in the home.

Solid fuel stoves have become very popular and you can even get ones with a glass front so you still get the visual appeal of the flames. A good installation will result in the closing off of the fireplace, which reduced a draft to the outside.

Heat loss directly from the fire is hugely reduced with over 65% staying in the house. And the reduction of the draft from the chimney means that more heat stays in the building.



image credit: J Mark Doddsmike appel via Compfight

Hiring An Insulation Specialist

For many people doing an insulation job on a home is not something they would attempt to do, so hiring a specialist is the only option. Other people may be DYI enthusiasts, but just not quite comfortable with certain types of insulation work.

In either situation, a specialist contractor with specific insulation experience is the best option, as they will be able to see a project through from start to finish. Their consultation should give you a clear idea of what you are getting and what your potential savings are.

A contractor will first of all help you determine what insulation options are most suitable to your specific building. Dependent on the age of the house, there may be certain limits, but a specialist will be able to say exactly what is suitable and what would have the best results. In some cases you may even be limited to exterior wall insulation.

The cost of each type of project, as well as different materials, will ultimately determine what you choose. But a good insulation specialist will be able to calculate the exact cost of a project and then outline what your energy savings will be over time.

One thing to keep in mind is that some types of insulation may not save you a lot of money in the short term, but will still improve the quality and comfort of a home immensely. This is especially the case in buildings that suffer from dampness, where there simply is no price that can be put on comfort.

Insulation Installation

Once you have decided on a certain type, the specialist will be able to take on the project and usually with a crew of workers get the job done in a much shorter time than you could do yourself. While some types of insulation are simple to do yourself, there is a certain level of comfort in having a professional get the job right from the start.

Before you hire a contractor, make sure you do some research into their previous work. Ideally you would hire one based on the recommendation of someone you know personally. But if this is not possible then definitely ask for some previous job references and contact those people.Some things you should ask previous customers is mainly about the accuracy of estimates, speed of job completion, quality of workmanship and maybe how accurate estimated savings were.Having all this information will make sure that you choose the right person to get the job done, with a certain level of confidence that you are not hiring a sub-par specialist with not enough experience.


Creative Commons License mycobond via Compfight

Exterior Wall Insulation

When insulating existing walls, blown in wall insulation is the most effective way of getting the job done. But some old buildings where there is very little or no cavity in the walls prove to be quite difficult to insulate in this way. This is where the method of exterior wall insulation comes into play, and sometimes proves to be the only effective solution.

The most common and popular method is using wall foam insulation. Polystyrene foam tiles are directly attached to the outside of the building, which in some cases is the only option.

When this method first came onto the market, there were very few options to the look of the exterior insulation. But today, there are many materials and colors available, including stone, timber or brick finish. This means that you can make your home look just like you want it to, by either applying a certain color, or have it blend into its surroundings with a timber cladding.

96 Maison de Fée

One of the biggest advantages of this form of insulating existing walls is that, when done properly, will pretty much eliminate cold and damp air penetrating the interior of a building. But if you have an existing problem with rising damp, then this is something you should have looked at by professionals first, as exterior wall insulation will not solve this problem.

With insulation applied to the exterior, it is important to consult professionals to do the installation, unless you are very confident in your DIY skills. It is very easy to get this kind of job wrong, and when not done correctly you could end up wasting an awful lot of time and money on wall foam insulation that does not solve your problems.

A great advantage of exterior insulation over interior insulation is that it can be done without disrupting the household, as all the work is done on the outside. However, be prepared to spend quite a lot of money to get the job done right. This still means that you get great savings per year, but it will probably take more than 10 years for you to get a financial return on your investment. When it comes to insulating the exterior of a building it is usually more about comfort of getting rid of a dampness problem, when blown in wall insulation is not an option.


image credit: nebojsa mladjenovic via Compfight

Most Common Thermal Insulation Materials

When it comes to insulation there are several options of home insulation types. Ultimately the choice of material will come down to affordability, as the more efficient the material is the more expensive.

There are three main types of thermal insulation materials:

  1. Fiberglass
  2. Cellulose
  3. Spray in polyurethane foam


By far the most commonly used material is fiberglass, which has been used for many years now. The raw material is transformed into a fibre like material in a pumping machine and once it is pumped out it does not settle. This means that it does not lose its effectiveness over time.


Fiberglass is also commonly used in rolls and batts which can be easily installed into attic spaces. It is however a more time consuming process that will cost more than blown in insulation.

Cellulose has become quite popular in recent years due to its environmental friendliness. Made of recycled paper and cardboard, it is applied similar to fiberglass. It is also a more natural product which a lot of people prefer to the alternatives.

Spray in foam is one of the most efficient, but also most expensive home insulation types. Once sprayed into place the foam expands just like spray shaving foam, which ensures that a cavity are is completely filled. Generally it is used to fill in small gaps around opening in buildings, like vents, windows and doors.

In addition to these common materials there are some options for insulating walls where there is no cavity to pump material into. The options here are to either apply internal or external wall insulation, directly to the wall.

For external insulation, the most commonly employed method is to attach tiles made of polystyrene directly on the outside of the building. This is quite a big job, and may be too big a job for most DIY enthusiasts. Bear in mind that if not done properly it can mean that maximum effectiveness is not achieved.

blown in insulationAnother commonly employed home insulation types are foil backed insulation. This is generally used to apply insulation to the interior of a wall. Essentially you get pieces of plasterboard or dry wall, which has a foil back to it that reflects heat. It is a very easy way to add internal insulation when there is no cavity to pump, but it is not one of the cheapest ways.

Today, all materials sold have to be fire resistant insulation. Whether fiberglass, cellulose or polystyrene, the thermal insulation materials have to be treated with fire resistant solutions. But it is always prudent to check the packaging to make sure that it is indeed fire resistant insulation.


image credit:  jude hill, Denis Collette via Compfight,