INDUSTRY SEGMENT INFORMATION (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 28, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 29, 2012	Sep. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 28, 2013 item	Dec. 29, 2012
INDUSTRY SEGMENT INFORMATION
Number of industry groups in which the entity operates									2
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	$ 33,606,000	$ 28,865,000	$ 32,857,000	$ 26,213,000	$ 29,919,000	$ 29,166,000	$ 29,747,000	$ 24,396,000	$ 121,541,000	$ 113,228,000
Depreciation, depletion and amortization	700,000	669,000	844,000	815,000	689,000	825,000	1,045,000	1,068,000	3,028,000	3,627,000
Operating (loss) income									(1,089,000)	(3,724,000)
Segment assets	71,962,000				71,545,000				71,962,000	71,545,000
Capital expenditures									2,686,000	1,833,000
Concrete, Aggregates & Construction Supplies
INDUSTRY SEGMENT INFORMATION
Revenues from external customers									42,922,000	40,231,000
Depreciation, depletion and amortization									2,093,000	2,736,000
Operating (loss) income									(3,782,000)	(4,991,000)
Segment assets	26,471,000				31,629,000				26,471,000	31,629,000
Capital expenditures									1,356,000	921,000
Doors
INDUSTRY SEGMENT INFORMATION
Revenues from external customers									15,821,000	12,690,000
Depreciation, depletion and amortization									126,000	138,000
Operating (loss) income									1,243,000	527,000
Segment assets	6,837,000				5,767,000				6,837,000	5,767,000
Capital expenditures									57,000	28,000
Heating and Cooling
INDUSTRY SEGMENT INFORMATION
Revenues from external customers									36,652,000	34,215,000
Depreciation, depletion and amortization									413,000	369,000
Operating (loss) income									2,938,000	1,736,000
Segment assets	18,748,000				17,054,000				18,748,000	17,054,000
Capital expenditures									718,000	417,000
Evaporative Cooling
INDUSTRY SEGMENT INFORMATION
Revenues from external customers									26,104,000	25,734,000
Depreciation, depletion and amortization									341,000	326,000
Operating (loss) income									2,070,000	2,129,000
Segment assets	12,118,000				12,250,000				12,118,000	12,250,000
Capital expenditures									548,000	458,000
Unallocated Corporate
INDUSTRY SEGMENT INFORMATION
Revenues from external customers									13,000	14,000
Depreciation, depletion and amortization									55,000	58,000
Operating (loss) income									(2,975,000)	(2,803,000)
Segment assets	7,654,000				3,840,000				7,654,000	3,840,000
Capital expenditures									7,000	9,000
Other
INDUSTRY SEGMENT INFORMATION
Revenues from external customers									29,000	344,000
Operating (loss) income									(583,000)	(322,000)
Segment assets	134,000				1,006,000				134,000	1,006,000
Construction Products
INDUSTRY SEGMENT INFORMATION
Number of reportable segments									2
Revenues from external customers									58,743,000	52,921,000
Depreciation, depletion and amortization									2,219,000	2,874,000
Operating (loss) income									(2,539,000)	(4,464,000)
Segment assets	33,308,000				37,396,000				33,308,000	37,396,000
Capital expenditures									1,413,000	949,000
HVAC Products
INDUSTRY SEGMENT INFORMATION
Number of reportable segments									2
Revenues from external customers									62,756,000	59,949,000
Depreciation, depletion and amortization									754,000	695,000
Operating (loss) income									5,008,000	3,865,000
Segment assets	30,866,000				29,304,000				30,866,000	29,304,000
Capital expenditures									$ 1,266,000	$ 875,000