The optimal R-value for most homes is 30, but you can go as high as 38 if you live in a tropical climate. Anything higher than 38 indicates an over-insulated space.
Using more insulation than required doesn't offer a significant advantage and can detrimentally affect how well your attic ventilates. If you've got well-installed attic insulation of a sufficient R-Value and still aren't pleased with the results, you may want to consider installing a radiant barrier.
Your walls or floors are always cold. Your home is drafty, especially in certain areas. You notice water leaks or moldy insulation, especially in attic spaces.
There comes a point where too much insulation starts to have a negative effect — financially, environmentally, and in terms of the longevity of your home. So yes, it is possible to over-insulate your house.
The cost to insulate a 2000-square-foot house can range from $2,000 to $6,000, depending on the type of insulation used and other factors.
We install the correct/optimal insulation levels for your attic R60, ceiling R38-60, sidewall R21, basement R13, and crawl space R13-38. Your budget is $3 per sq ft for insulation which includes additional considerations.
Still, certified attic specialists may also use them during a major remodeling project. In open-cell spray foam installations, the typical R-value ranges from 3.5 to 3.6; in closed-cell spray foam installations, the average ranges from 6.0 to 6.5.
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.
If we wish to label the strength of the association, for absolute values of r, 0-0.19 is regarded as very weak, 0.2-0.39 as weak, 0.40-0.59 as moderate, 0.6-0.79 as strong and 0.8-1 as very strong correlation, but these are rather arbitrary limits, and the context of the results should be considered.
Adding two R-13, 3.5” batts to a 2”x6” (5.5”) wood stud cavity will not provide an R-26. The total of 7” of insulation is reduced in thickness to 5.5” thereby losing the R-value associated with its full thickness.
Roof and ceiling insulation. Installing roof and ceiling insulation can save up to 45% (or more) on heating and cooling costs.
In fact, adding too much insulation to your walls can lead to problems such as poor ventilation, mould growth, and condensation. This is because thicker insulation can block airflow and trap moisture, leading to indoor air quality issues and even structural damage.
One sign of good insulation is having even temperatures throughout your home. If different rooms have different temperatures – say, you freeze in the kitchen but feel too warm in your living room – that's a clear sign your house is under-insulated.
Part L of the UK Building Regulations outlines that roof and loft insulation in existing dwellings should be able to achieve a u-value of at least 0.16 W/m²K. This equates to about 270mm of mineral wool, or lesser thicknesses for more thermally efficient insulation materials.
However, it is possible to have too much insulation. If there is too much insulation, and it comes in contact with the roof sheeting, it can block air circulation, which can lead to condensation, mould and mildew.
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.
The dip from R10 to R4 seems odd, as one would expect more R as you travel further north through the zones. Thicker is not better! Doubling the amount of insulation will double the R-Value, but so what? Doubling the insulation from R-19 to R-38 does NOT cut the heat loss in half (50%) it cuts it by around 3%!
The higher the R value, the more your mat resists heat loss and the better it insulates you from the cold ground. As a rule of thumb, an R value of 1.0 to 2.0 is fine for summer use but you'd need a rating of 4.0 to 5.0+ for winter camping.
The recommended attic insulation R-value is R-50 or higher. Proper attic insulation R-value helps maintain a comfortable indoor temperature and reduces energy consumption significantly. Upgrade your attic insulation to improve energy efficiency, prevent heat loss, and enhance overall comfort in your home.
Yes, too much loft insulation can cause dampness in some situations. Loft insulation works by trapping warm air inside a building, preventing it from escaping through the roof. This helps to keep the interior of the building warmer in cold weather, reducing the need for heating and saving energy.
Now, to answer whether R-Value can be too high, the answer is technically no. The higher the R-Value, the better the insulation will reduce heat transfer. However, a few things to remember when choosing an insulation R-Value.
Also, when laying down additional insulation, work from the perimeter toward the attic opening. Never lay insulation over recessed light fixtures or soffit vents. Keep all insulation at least 3 inches away from recessed "can" lights, unless they are rated IC (Insulated Ceiling).
Do you have any plans for furnishing/fitting out your attic in the future? Then you could simply insulate the pitched roof. But the best solution is actually to insulate both the attic floor and the underside of the roof.
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.