Compare polystyrene and mineral wool

Builders often argue about which insu­la­tion is bet­ter to choose for cer­tain con­di­tions. Some say — poly­styrene, oth­ers insist on the good old min­er­al wool. In gen­er­al, both options are great for home insu­la­tion, since they have almost iden­ti­cal ther­mal con­duc­tiv­i­ty coef­fi­cients. But oth­er than that, they are rad­i­cal­ly dif­fer­ent. Our experts under­stood the ques­tion: what is bet­ter — poly­styrene or min­er­al wool?

Choosing the best

In order to accu­rate­ly deter­mine for your­self the opti­mal­i­ty of a par­tic­u­lar insu­la­tion, you need to clear­ly under­stand the fea­tures of each. Our ana­lysts made a detailed com­par­i­son of both mate­ri­als on a num­ber of impor­tant cri­te­ria.

Life time

Some mis­tak­en­ly believe that the foam becomes com­plete­ly unus­able after 7–10 years of ser­vice. In real­i­ty, such an unpleas­ant sit­u­a­tion occurs only when the mate­r­i­al is put into oper­a­tion incor­rect­ly, name­ly: in the absence of a pro­tec­tive coat­ing. If it is, no rain or sun can adverse­ly affect the foam. As for min­er­al wool, due to its struc­tur­al fea­tures (mate­r­i­al fibers are usu­al­ly made with the addi­tion of vol­canic rocks), the impact of an aggres­sive envi­ron­ment does not in any way affect the state of the insu­la­tion.

Environmental friendliness

A few years ago, in the man­u­fac­ture of foam, styrene was used as the base, and fre­on gas was used in the pro­duc­tion process of this insu­la­tion. As a result, such mate­r­i­al could not be used for fin­ish­ing the inte­ri­or liv­ing quar­ters of the house, since it emit­ted harm­ful gas­es. Cur­rent­ly, man­u­fac­tur­ers have aban­doned the use of fre­on in the man­u­fac­ture of foam. Nev­er­the­less, you should not get car­ried away with the amount of this insu­la­tion when dec­o­rat­ing inte­ri­or spaces. Min­er­al wool has no such restric­tions.

combustibility

In this mat­ter, min­er­al wool is the absolute leader — it sim­ply does not burn. By the way, some vari­eties of this insu­la­tion (basalt) are able to with­stand the effects of record high tem­per­a­tures — up to 1000 ⁰C. Expand­ed poly­styrene will burn with a bright flame. It is known that flame retar­dants are added to the foam to pre­vent com­bus­tion. Only their prop­er­ties grad­u­al­ly weak­en and the insu­la­tion becomes unable to with­stand fire.

Heat loss resistance

The ther­mal con­duc­tiv­i­ty coef­fi­cients of both heaters are approx­i­mate­ly the same. But, as prac­tice has shown, poly­styrene, nev­er­the­less, is more reli­able in this mat­ter. Why? It’s sim­ple: only dense basalt wool (slab) can com­pete in terms of ther­mal con­duc­tiv­i­ty with expand­ed poly­styrene, which can­not be said about rolled prod­ucts.

Steam capacity

The coef­fi­cient of vapor per­me­abil­i­ty of the foam (regard­less of the vari­ety) is 0.3 mg / m.ch. Pa. A sim­i­lar coef­fi­cient of min­er­al wool exceeds this fig­ure by 10 times. And, there­fore, it pass­es the evap­o­rat­ed mois­ture many times bet­ter. Prac­tice has shown that usu­al­ly the insu­la­tion of walls is mul­ti-lay­ered, and each lay­er has its own vapor trans­mis­sion capac­i­ty. The final vapor per­me­abil­i­ty is eval­u­at­ed by the mate­r­i­al with the low­est val­ue. In gen­er­al, heaters are equat­ed to each oth­er.

It is impos­si­ble not to men­tion some fea­tures of both heaters. So, for an insu­lat­ing sys­tem with a poly­mer struc­ture, it is unde­sir­able to use min­er­al wool, since both the base and the out­er lay­er will not pro­vide suf­fi­cient mois­ture pas­sage. The rule is sim­ple: mate­r­i­al with bet­ter vapor bar­ri­er is laid clos­er to the out­side of the house. Sty­ro­foam does not let steam through, but does not accu­mu­late either. From the inside, steam comes out only through the joints, defects in the fin­ish. Whether this is a plus or a minus is hard to say.

Ease of installation

Both con­ven­tion­al and extrud­ed foam are very resilient and strong, so there are no prob­lems when sand­ing or break­ing into frag­ments. But there are dif­fi­cul­ties with fix­ing on the wall sur­face: cold bridges are almost inevitable at the junc­tions of indi­vid­ual ele­ments. You can solve the prob­lem by using sheets with an L‑shaped edge. As for min­er­al wool, it can­not boast of high den­si­ty (except for mats laid in the facade). But she is com­plete­ly unaware of any bridges of cold.

Features of the use of heaters

Not many peo­ple know that min­er­al wool and poly­styrene foam can behave dif­fer­ent­ly under dif­fer­ent oper­at­ing con­di­tions. This means that both options are not always suit­able for the same object.

Poly­foam is best suit­ed in the fol­low­ing cas­es:

1. For base­ment-free hous­es with a mono­lith­ic foun­da­tion, foam plas­tic slabs are placed on a lev­eled area and poured with con­crete.

2. For insu­la­tion of under­ground struc­tures — poly­styrene is not afraid of mois­ture from the ground, so it is best suit­ed for such pur­pos­es. Even after decades, engi­neer­ing struc­tures will be reli­ably pro­tect­ed from the effects of cold.

3. For wall insu­la­tion in block / brick hous­es — the mate­r­i­al will pro­tect the premis­es from heat loss with­out the risk of a dew point (steam to mois­ture con­ver­sion).

4. For non-ven­ti­lat­ed (warm, flat) roofs — foam plas­tic will per­fect­ly pro­tect such a struc­ture from the cold, pre­vent­ing the for­ma­tion of con­den­sate.

5. For insu­la­tion of floors — foam boards per­fect­ly insu­late both floors and floors with the oblig­a­tory use of an insu­lat­ing lay­er.

Min­va­ta are suit­able in such cas­es:

1. For insu­la­tion of attics, pitched roofs — there is no bet­ter option than min­er­al wool (if there is ven­ti­la­tion).

2. For insu­la­tion of hous­es built of wood — for “breath­ing” walls, foam plas­tic is the worst option, since it actu­al­ly lev­els out the use­ful prop­er­ties of wood. Min­va­ta is the per­fect solu­tion.

3. For warm­ing low-rise brick hous­es — only if the min­er­al wool will act as a mid­dle lay­er of ther­mal insu­la­tion.

4. For insu­la­tion of heat­ed objects — min­er­al wool will per­fect­ly pro­tect against heat, with­stand­ing tem­per­a­tures up to 1000 ⁰FROM.

5. For insu­la­tion of frame build­ings — and the insu­la­tion is equal­ly good for sur­faces of dif­fer­ent angles of incli­na­tion.

6. For cov­er­ing par­ti­tions / ceil­ings in hous­es made of any mate­ri­als.