1
                                                                      EXHIBIT 12


             AMERICAN PLUMBING & MECHANICAL, INC. AND SUBSIDIARIES
                       RATIO OF EARNINGS TO FIXED CHARGES
                           (IN THOUSANDS OF DOLLARS)





                                                                Four Months    Four Months       Year Ended       Three Months Ended
                                   Years Ended August 31,          Ended          Ended         December 31,            March 31,
                               ------------------------------   December 31,   December 31,  ------------------   ------------------
                                 1994       1995       1996        1995           1996         1997       1998     1998       1999
                               -------    -------    --------   ------------   ------------  -------    -------   ------    -------
                                                                                                  
CHRISTIANSON (ACCOUNTING
   ACQUIROR)
Earnings:
   Income before income
      taxes . . . . . . . . .  $   256    $   838    $  1,343     $    370       $(1,402)    $ 1,967    $   648   $  449    $ 3,564
   Fixed charges  . . . . . .       93        133         152           49            52         252        269      165        197
                               -------    -------    --------     --------       -------     -------    -------   ------    -------
                               $   349    $   971    $  1,495          419       $(1,350)    $ 2,219    $   917   $  614    $ 3,761
                               =======    =======    ========     ========       =======     =======    =======   ======    =======

Fixed Charges:
   Interest expense . . . . .  $    10    $    72    $     92     $     29       $    33     $   102    $   116   $   37    $    27
   Portion of rental cost
      representing interest .       83         61          60           20            19         150        153      128        170
                               -------    -------    --------     --------       -------     -------    -------   ------    -------
                               $    93    $   133    $    152           49       $    52     $   252    $   269   $  165    $   197
                               =======    =======    ========     ========       =======     =======    =======   ======    =======
Ratio of earnings to fixed
   charges  . . . . . . . . .      3.7x       7.3x        9.9x         8.6X           --x        8.8x       3.4x     3.7x      19.1x
                               =======    =======    ========     ========       =======     =======    =======   ======    =======

PRO FORMA COMBINED:
Earnings:
   Income before income
      taxes . . . . . . . . .                                                                           $18,710             $ 8,395
   Fixed charges  . . . . . .                                                                            16,412               4,114
   Preference dividends . . .                                                                            (1,363)               (341)
                                                                                                        -------             -------
                                                                                                        $33,759             $12,168
                                                                                                        =======             =======
Fixed Charges:
   Interest expense . . . . .
   Amortized premiums,
      discounts and
      capitalized expenses                                                                              $14,201             $ 3,550
      related to debt . . . .                                                                               500                 125
   Portion of rental cost
      representing interest .                                                                               348                  98
   Preference dividends . . .                                                                             1,363                 341
                                                                                                        -------             -------
                                                                                                        $16,412             $ 4,114
                                                                                                        =======             =======
Ratio of earnings to fixed
   charges  . . . . . . . . .                                                                               2.1x                3.0x
                                                                                                        =======             =======