It is strongly advised not to fit 270mm of mineral wool and squash it down with boarding or any other items, as this will reduce efficiency and be ineffective at insulating your home.
Squashing Reduces Thermal Performance: Compressing insulation can decrease its ability to trap air and prevent heat from escaping. Studies have shown that squashing insulation from 270mm down to 100mm will reduce its performance by over 50% significantly affecting your home's energy efficiency.
What Happens If You Compress Blown-In Insulation? Like batts, compressing blown-in fiberglass insulation improves the R-value per square inch while diminishing the overall R-value. Also like fiberglass batts, some amount of compression is OK if the cavity is completely filled.
Make sure you don't squash the mineral wool when you fit the boards on top, as this will reduce its insulation value.
Don't compress insulation, that removes the air content which renders it useless.
Fiberglass and rock wool batts—2x4 walls can hold R-13 or R-15 batts; 2x6 walls can have R-19 or R-21 products.
One way that excessive loft insulation can cause dampness is by blocking ventilation. Proper ventilation is necessary to allow moisture to escape from the building. If insulation is installed too thickly or packed too tightly into the loft, it can block air flow and prevent moisture from escaping.
Removing old insulation is generally recommended if it's damaged, contaminated with mold, or infested with pests. However, if the insulation is in decent shape and just needs a boost, adding a new layer on top can be a cost-effective option.
Cutting our slabs is simple, using a sharp, long-bladed knife or insulation saw. Accurately measure out how much you need to cut to avoid leaving gaps. Don't squash down any existing insulation.
Do make sure your whole loft floor is covered with insulation with a minimum thickness of 100mm (ideally 270mm for maximum thermal efficiency). Don't lay it right up to the edges where the sloping roof meets the outside wall (known as the eaves) – ensure there's a gap for airflow which will help to avoid condensation.
Moisture damage
This can occur due to leaks in the roof or foundation, inadequate ventilation, or high humidity levels inside a building. Moisture can cause the insulation material to become compressed and lose its effectiveness, leading to increased energy consumption and potential mold growth.
You will want to bring up your attic up to R-38:
If your attic has 5-6″ of existing insulation, you'll want to install an R-19 to achieve a total of R-38.
However, there may be times when insulation is compressed to fit specific needs. While fiber glass insulation can be compressed below labeled thickness and still achieve Grade I installation, manufacturers' instructions specify installation without compression to achieve labeled R-value.
Insulation levels are specified by R-Value. R-Value is a measure of insulation's ability to resist heat flow. The higher the R-Value, the better the thermal performance of the insulation. The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.
It is possible to over-insulate your house so much that it can't breathe. The whole point of home insulation is to tightly seal your home's interior. But if it becomes too tightly sealed with too many layers of insulation, moisture can get trapped inside those layers. That's when mold starts to grow.
Compressing the insulation will cause it to lose its effective R-Value – instead install ROCKWOOL Comfortbatt R-15.
Insulation can help reduce noise pollution from showers or other bathroom appliances in shared living spaces. Does a basement ceiling need a vapour barrier? Installing a vapour barrier is optional when utilising ROCKWOOL solutions, as stone wool insulation is water repellent.
What happens if ROCKWOOL insulation gets wet? ROCKWOOL stone wool insulation is moisture resistant yet vapor permeable. This means that in the event the insulation becomes damp or wet, the insulation can be allowed to dry out.
Unfortunately, the majority of homes built 50 years ago were not insulated at all. It is important to be aware of these insulation issues if your home is 50+ years old. Replacement (or new installation) may be necessary if your home is drafty, if you have high utility bills, etc.
Improved Indoor Air Quality. Removing your attic's old insulation can significantly improve indoor air quality. Indoor air quality plays a crucial part in overall health and wellness. Old attic insulation can host contaminants such as rodent urine and feces.
Too much insulation will leave humidity and moisture to accumulate in your attic space. This can lead to mold growth on your walls and insulation. There might also be water damage to the support beams in your home's roof.
It is strongly advised not to fit 270mm of mineral wool and squash it down with boarding or any other items, as this will reduce efficiency and be ineffective at insulating your home. Instead, place mineral wool between the joists and then fit rigid insulation boards across the joists, with floorboards on top.
How many degrees of difference insulation makes on its own depends on the type of home you have, what the weather is like and what kind of insulation you have. Depending on what you choose, you could see a five- to 20-degree temperature difference just based on the insulation alone.
You'll need to start laying with a minimum gap of 25mm between the eaves and the insulation to ensure a suitable air gap. Maintain this gap along two opposite sides of the loft.