Frequently Asked Questions - Rammed Earth Artisan
Is Rammed Earth construction suitable for all climates?
With the strategic use of stabilizers, insulation, admixtures, and intelligent design, rammed earth is a viable and attractive building method in any climate.
How does one deal with electrical and water lines?
Services need to be well-planned in advance to minimize difficulties.
Electrical – Conduit and boxes can be rammed in place inside the walls during the construction process.
Water – If possible, choose to run them externally, in hidden wall chases, or under floors. If you cannot avoid running water lines in the walls, it is possible to integrate oversized metal pipe into the walls which will allow you to feed PEX tubing through them after rammed earth construction is complete.
What is the R-value of rammed earth? How well does it insulate?
Indoor temperature comfort is generally achieved by insulation or thermal mass, or a combination of both. Focusing solely on R-Values to determine the performance and comfort of an indoor environment, ignores the contribution of thermal mass.
Technically, rammed earth is not a great insulator, as it performs at about R-0.25 to R-0.75 per inch. However, it is a highly effective thermal mass and stores large amounts of heat (or cold) that is then passively radiated back to the indoor environment when it is needed to maintain comfortable temperature.
In climates where insulation is required, rigid insulation is embedded in the interior of the RE wall, thus forming inner and outer wythes sandwiching an insulative core.
Depending on final wall thickness, R-values of over 40 are possible, though the performance of these walls would rate much higher than a standard R-value metric would indicate, due to their ability to produce a thermal flywheel effect and act as a heat sink and diffuser.
How thick are the Rammed Earth Walls?
Rammed Earth Artisan has experimented with panels as thin as ¾”, but generally, for a non-insulated wall it is ideal to make them at least 12”. Insulated walls are 18 to 24” thick.
Can I mount cabinets and hang pictures on a rammed earth wall?
Yes. Many standard masonry fasteners are suitable for use in rammed earth walls, though they will need to be set further in from edges than with concrete.
Is it more expensive than conventional stick frame construction?
Short-term: Dependent upon design, upfront costs can be slightly to significantly more than conventional stick frame construction and more in-line with quality masonry construction.
Long-term: If you consider maintenance and lifecycle costs, heating and cooling expenses, environmental and health benefits, and a myriad of other factors, rammed earth works out to be more affordable than conventional construction.
Note: Given the recent dramatic increase in the price of lumber, rammed earth should be a serious consideration for an alternative building material.
Are there any concerns when building with Rammed Earth?
There are a few things to consider and be aware of:
A rammed earth wall may include surface irregularities, shrinkage cracks, and visible cold joints. If the wall is properly constructed, none of these issues will be structural defects, merely aesthetic imperfections that are due to the inherent characteristics of rammed earth construction. For many, these imperfections are part of the allure of rammed earth construction.
The thick walls occupy a significantly larger footprint than conventional walls.
Most General Contractors are unfamiliar with rammed earth construction and they may not be as enthusiastic about the process as the client, designer, and we are.