Can you have too much loft insulation?

Lofts can't just chip off a layer of insulation, so the need to breathe is far more important. So, can too much loft insulation cause condensation? Yes it can, and it can cause havoc in your home as well.

What happens if you put too much insulation in your attic?

It's possible to over-insulate an attic as too much will cause moisture buildup and eventually result in mold. Eventually, adding more insulation leads to diminishing returns in trapping heat as well.

Is 400mm loft insulation too much?

We'd recommend everything in moderation. While some people argue that an over-insulated house could cause damp, mould and other issues. Typically, upping your loft insulation from 270 mm to 400 mm isn't really going to make a big difference, and so it's probably worth sticking with the lesser amount.

Can you put too much insulation in?

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.

Is it worth adding extra loft insulation?

Financial saving

The most obvious difference offered by an insulated loft is the saving in energy bills, and it's very simple here. It's estimated that a quarter of all the escaping heat from a building goes through the roof. If that could be stopped, your bills should be reduced by a quarter.

How to Calculate How Much Loft Insulation You Will Need

Can too much insulation cause condensation?

Moisture and insulation

Improperly installed insulation is one of the leading causes of condensation in the attic, especially when too much insulation traps warm air up near the roof and forces condensation.

Should I remove old loft insulation?

In most circumstances removing your old insulation isn't necessary and it can actually be quite beneficial to leave it. This is as most insulation will retain its thermal properties so leaving it in place will mean that you continue to benefit from it whilst also having an additional layer of insulation on top!

How much insulation should you have in your attic?

According to the U.S. Department of Energy, it's recommended that attics have an R-38 to R-49, or about 12” to 15” of fiberglass or cellulose insulation. Use unfaced insulation when adding more insulation to an attic that already has some insulation, laying the rolls or batts at right angles to the floor joists.

How thick should loft insulation be UK?

If you can get into the loft, measure the thickness of the insulation that's already there. Since 2003, current building regulations recommend a depth of at least 270mm (mineral or glass wool) in the loft – use this as a starting point rather than a finishing line to see larger savings.

Can too much loft insulation cause damp?

Does Loft Insulation Directly Cause Damp? The simple answer to this is no. Loft insulation in itself is not responsible for damp appearing in your property – however, it can be a contributing factor when it comes to the spread of damp via condensation.

Should loft insulation go to the edges?

Insulation should be continued right to the edge of the ceilings but it shouldn't block the eaves' ventilation. Ventilation is vital to ensure the necessary air movement to prevent condensation from water vapour, as this can lead to decay of the structural timbers.

Can I put loft insulation on top of boards?

Yes you can most certainly overlay and additional layer of insulation over the chipboard. I would leave the insulation short at the eaves though to ensure there is adequate ventilation in the loft space. This would most certainly improve you homes thermal performance during winter months.

How much insulation is too much?

How Much Insulation is Too Much? In Southern California, you'll want to shoot for an R-Value of around 30 for an optimum experience. The California Department of Energy's 2019 Building Envelope requirements state the minimum R-Value for wood-construction ventilated attic spaces in California is R-22.

Is R60 attic insulation worth it?

Recommended R-Value Varies by State

You need exactly as much as the area you live in determines. Here, where temps get pretty hot for much of the year, attics should have from R30 to R60 (average is R38). Those living up north want anything from R49 to R60. This helps insulate against the extreme cold weather.

Can you lay loft insulation over joists?

If access is easy and your loft joists are regular, you can use rolls of mineral wool insulation. The first layer is laid between the joists – the horizontal beams that make up the floor of the loft – then another layer is laid at right angles to cover the joists and make the insulation up to the required depth.

Can you put new insulation over old?

You can absolutely new insulation over old insulation… as long as it isn't wet. Energy Star advises as follows: “If it… appears that the insulation [is wet or] has previously been wet, you should look for the cause and repair the problem to prevent a reoccurrence. Remove any wet insulation.

Should you insulate the underside of your roof?

In order to avoid damage to the roof deck, you should insulate ceilings to create an air barrier between the living space and an unfinished attic or airspace underneath the roof deck.

How do I know if my attic needs more insulation?

Looking across your attic, if the insulation is level with or below the attic floor joists, you probably need to add more insulation. Assumes R-3/inch. If you cannot see any of the floor joists because the insulation is well above them, you probably have enough, and adding more insulation may not be cost-effective.

Is 6 inches of attic insulation enough?

Most joists are six to seven inches tall, and if they are completely filled with material, they are insulated at R-21. However, the DOE recommends that attics in Southern homes be insulated with 13 to 14 inches, or R-38, of insulation at minimum.

How do you tell if attic is well insulated?

Do you need an air gap for insulation?

Insulation is technically a solid with a lot of air in it therefore, it is NOT an air gap. You literally must have a VOID, nothing in the air gap except air itself. So if you are installing under a roof or in a wall, you must create an air gap.

Does loft insulation deteriorate over time?

The simple answer is 'yes'. Insulation is not designed to last forever, eventually it will begin to degrade and whilst you may not always be able to see the deterioration, you'll certainly notice it.

How often should attic insulation be replaced?

As a general rule, insulation should be replaced or retrofitted every 15 to 20 years. However, it may need replacing or retrofitting sooner depending on the type of insulation installed, the R rating of the original insulation, compression and movement over time, and whether any damage has occurred.

Why is my attic wet in the winter?

The source of moisture in the attic is from moisture in the home. If the attic is not properly vented to allow the moisture to escape, moisture will build up and condensation will occur on the underside of a cold roof in the winter.

Should a loft be damp?

Principally you must ensure that the loft is effectively ventilated in order to improve air flow and to allow damp air to disperse outside rather than settle on loft surfaces. In an attempt to do his you may want to: Ensure ventilation slots in the roof space are unobstructed.