Install staple up radiant floor heating system

Using heat transfer plates will disburse heat more evenly throughout the floor than the other under-floor methods. Most manufactures will make heat transfer plates to accept different sizes of tubing. So you need to match the width of your heat transfer plates to the size of your tubing. Heat transfer plates also range anywhere from 5 to 12 inches wide depending on the brand you choose. You will want to get the best plate coverage possible. If using narrow plates, you should run two rows between each floor joist.

Check each heat transfer plate before you insert them into the tubing. Be aware of any sharp edges on the transfer plates as they might cut or damage the tubing. Installation is easy, simply snap the plate around the tubing and fasten it to the underside of the sub-floor. Simply make certain that each heat transfer plate is stapled up in the center of the floor joists.

When you staple up the plates, staples towards the outside edges of the plate as well as one row of staples down the middle. If you can only do this once because the ceiling will be finished then the answer is absolutely yes. The amount of insulation is dependent on what is above and below. If there is carpeting or a high heat loss area above then you should put in R If not, you can probably get away with R but R is better.

If there is an unheated basement below then you should use R If the heat loss downward is entirely wasted to a crawl space, for example, then your insulation method should be extensive.

You should try to get in a minimum of R Some will insulate between the joists with fiberglass and then seal the entire underside with rigid foam. If the ceiling will not be finished, some will wait and see how the system performs and then add the insulation after if necessary.

While it is simple, it is very important to do it correctly. If it is not, you can have a floor heating system that is inefficient, costly to operate, and may not work at all. Here are some general guidelines to follow. Keep in mind that these recommendations are general in nature and you should always consult your code official for proper installation. On top of your compacted earth or sand, you should install a vapor barrier.

Studies show that this may not be effective as other options. You should check with your code official for code compliance.

This website is a good resource for why and how to install the vapor barrier. Once the vapor barrier is in, you should insulate the slab from the earth. Extruded or expanded polystyrene rigid blue or pink board is the material of choice. These products claim a high R-value but most of this comes from its reflective properties. You lose the reflective properties of the material once you pour concrete over it.

Crete-heat is the name of one product that many of our customers use. This product has nubs on top to hold the tubing in place. All you have to do is walk the tubing in place, step it down between the nubs and keep going.

There is no need for spending extra time bending over and tying the tubing to the mesh or rebar. Crete-heat has a built in vapor barrier and is tongue and groove so it snaps together. There is no need to tape any of the seams. Since much of the heat loss in a concrete slab actually occurs on the outer edge, it is important that we insulate there as well.

Here are a couple of details. The first shows what happens if only the side edge is to be insulated. The second depicts the proper way to insulate a concrete slab when used for radiant underfloor heating. Keep in mind that some will insulate the side edge all the way down to the footing. For more details on insulating methods, please read our Design and Construction Suggestions Manual. Once the insulation is in, the next step is to layout the radiant tubing.

If you install the Crete-heat product then this part is easy. Simply step the tubing into the nubs. If you used traditional foam board then you still have a couple of options.

Some will staple the tubing down to the foam using Pex staples and a special gun which makes the work go quickly. The only downfall is that the staples can be somewhat expensive.

Another option is to attach the tubing to the wire mesh or rebar using zip ties. This is the most common method because the zip ties are inexpensive and most are willing to sacrifice a little time if it means saving a lot of money.

These are also called heat transfer plates or aluminum fins. A study conducted by Kansas State University some years ago showed that systems using heat transfer plates vs.

The significance is that you can typically lower the water temperature and reduce cycle times which can lower your operational cost. Radiantec also conducted our own plate study experiments and you can find the results here.

The most cost effective solution is to install the thin heat transfer plates in continuous coverage. Staple-up radiant install showing difference in plated vs. This picture shows the benefits of full aluminum heat transfer plate coverage vs. Both areas were on the same zone and operated for the same amount of time. Our general rule of thumb is to space the aluminum plates continuously in carpeted rooms, bathrooms, and high heat loss areas such as great rooms.

Aluminum heat transfer plates in continuous coverage. Photo of aluminum reflective barrier installed in one joist bay for radiant floor heating. Insulation is usually put in after this see next step so if you can find a foil faced insulation with high enough R-value, you can forgo this product.