A common question homeowners often ask is, “Can you put new insulation over old insulation?” In most cases, the answer is "yes," but there are several important factors to consider before proceeding.
Adding new insulation to existing insulation can be highly beneficial, especially in areas that suffer from heat loss or that are difficult to keep at a comfortable temperature.
Several parts of the home can benefit from additional insulation, including:
- Attic: is one of the main sources of heat loss in most homes.
- Basement: helps prevent cold floors and drafts.
- Exterior walls: Insulating these walls can significantly improve energy efficiency.
- The crawl space: Proper insulation here can prevent moisture and reduce energy consumption.
- Garage: Insulating this area can enhance temperature regulation and improve the comfort of nearby rooms.
If you’re thinking of adding new insulation over old, the answers to common questions below will help guide you. However, before going the DIY route, it’s always a good idea to consult a professional for a thorough assessment of your home’s insulation needs.
Do I Need to Remove Old Insulation Before Installing New Insulation?
In most situations, removing old insulation is not necessary when adding new layers. Old insulation can often be left in place if it’s still in good condition and hasn’t been compromised by moisture or pests.
However, you should first have your insulation assessed by a professional to ensure everything is suitable for adding new material.
Here are key considerations before adding new insulation:
- Current insulation levels: You may not need to add much if your home already has sufficient insulation.
- Type of insulation: Some insulation types are incompatible, so it's important to know what material you're working with.
- Condition: If your existing insulation is damaged, damp, or infested by pests, it should be removed.
- R-value: This measures the insulation’s ability to resist heat flow. Make sure the new insulation won’t negatively affect the overall R-value.
Removing old insulation can be time-consuming but is necessary if the material has been compromised by water or animals. In such cases, it’s best to replace the damaged insulation entirely rather than adding new layers.
Can You Put Blown-In Insulation Over Batt Insulation?
Batt insulation, typically made from materials like fibreglass, mineral wool, or cellulose, is commonly found in homes. Blown-in insulation, which is applied using specialised equipment, can be effectively added over batt insulation if the batt is still in good condition.
For example, you can enhance your attic insulation by adding blown-in insulation on top of batt insulation. Many homeowners opt to mix materials like cellulose with fibreglass batts, which can improve the overall insulation performance.
Can You Lay Rolled Insulation Over Blown-In Insulation?
Blown-in insulation is often used in areas like attics due to its ability to fill tight spaces. It is possible to add rolled insulation (also known as blanket insulation) on top of blown-in insulation, but you should take care to use unfaced insulation.
Faced insulation has a vapour barrier, and placing this barrier on top of blown-in insulation can trap moisture, leading to condensation and potential mould issues.
For best results, use unfaced insulation when adding rolled insulation over blown-in material.
Can You Blow Insulation Over Existing Insulation?
Blown insulation can generally be added on top of existing insulation, but this depends on the type of insulation already in place. It works well with fibreglass, cellulose, and other loose-fill materials. However, you must ensure that the old insulation is dry and in good condition before adding new material.
If your home’s walls are insulated with spray foam, additional insulation can be added, provided the spray foam is completely dry. The key is ensuring the insulation materials are compatible and won’t cause any moisture-related issues.
Can Insulation Be Blown Into Existing Walls?
When it comes to upgrading wall insulation, homeowners often worry about having to tear down walls. However, blown-in insulation offers a solution. By making small openings in the walls, contractors can inject loose-fill insulation into wall cavities without the need for extensive construction work.
However, it’s important to use the correct amount of insulation. Too little won't to an acceptable extent insulate the walls, and too much can restrict airflow, leading to condensation and potential mould growth. It’s crucial to get this done by an experienced professional to avoid issues later on.
Can You Put a Vapour Barrier Over Faced Insulation?
Faced insulation already comes with a vapour barrier—usually made of paper or foil—that helps prevent moisture from entering. Adding an additional vapour barrier, such as plastic sheeting, on top of faced insulation is not advisable.
Doing so can trap moisture between the two layers, potentially causing condensation, mould growth, and damage to the insulation and building materials.
If moisture is a concern, it’s best to use unfaced insulation with a properly installed vapour barrier to ensure satisfactory moisture control.
Conclusion
So, adding new insulation over old can greatly enhance your home’s energy efficiency and comfort. However, it is crucial to carefully assess the condition of your existing insulation, ensure material compatibility, and manage moisture properly for the best outcome.
Moreover, if you're uncertain about the next steps, BuildPro is here to assist. With our professional expertise, we can guide you through the process and recommend the most suitable insulation solutions.
Don’t hesitate—contact BuildPro today for expert advise and take the first step towards a more energy-efficient and comfortable home!
