▁of ▁engine ered ▁flo ors . ▁ ▁Ad hes ives ▁The ▁types ▁of ▁ad hes ives ▁used ▁in ▁engine ered ▁wood ▁include : ▁U rea - form al de hy de ▁res ins ▁( U F ) ▁most ▁common , ▁che apest , ▁and ▁not ▁water proof . ▁Ph en ol ▁formal de hy de ▁res ins ▁( PF ) ▁yellow / b rown , ▁and ▁commonly ▁used ▁for ▁exterior ▁expos ure ▁products . ▁Mel am ine - form al de hy de ▁res ins ▁( M F ) ▁white , ▁heat ▁and ▁water ▁resist ant , ▁and ▁often ▁used ▁in ▁exposed ▁surfaces ▁in ▁more ▁cost ly ▁designs . ▁polym er ic ▁M eth yl ene ▁di phen yl ▁di is oc yan ate ▁( p M DI ) ▁or ▁poly ure th ane ▁( PU ) ▁res ins ▁expensive , ▁generally ▁water proof , ▁and ▁does ▁not ▁contain ▁formal de hy de , ▁not or iously ▁more ▁difficult ▁to ▁release ▁from ▁plat ens ▁and ▁engine ered ▁wood ▁press es . ▁▁ ▁A ▁more ▁inclus ive ▁term ▁is ▁struct ural ▁compos ites . ▁For ▁example , ▁fi ber ▁c ement ▁s iding ▁is ▁made ▁of ▁c ement ▁and ▁wood ▁fi ber , ▁while ▁c ement ▁board ▁is ▁a ▁low - dens ity ▁c ement ▁panel , ▁often ▁with ▁added ▁res in , ▁faced ▁with ▁fi berg lass ▁mesh . ▁ ▁Health ▁concerns ▁ ▁While ▁formal de hy de ▁is ▁an ▁essential ▁ing red ient ▁of ▁cell ular ▁met abol ism ▁in ▁m amm