INDUSTRY SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015 USD ($)	Sep. 27, 2014 USD ($)	Oct. 03, 2015 USD ($) item	Sep. 27, 2014 USD ($)	Jan. 03, 2015 USD ($)
INDUSTRY SEGMENT INFORMATION
Number of industry groups in which the entity operates | item			2
INDUSTRY SEGMENT INFORMATION
Number of reportable segments | item			2
Revenues from external customers	$ 36,165	$ 34,366	$ 101,715	$ 98,557
Depreciation, depletion and amortization	640	764	1,937	2,245
Operating (loss) income	965	(6,517)	1,377	(7,168)
Segment assets	77,630	71,801	77,630	71,801	$ 71,801
Capital expenditures	859	132	1,379	1,637
Concrete Aggregates and Construction Supplies [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	16,759	16,185	41,414	43,526
Depreciation, depletion and amortization	330	483	1,007	1,403
Operating (loss) income	686	(6,376)	(170)	(7,734)
Segment assets	33,814	30,800	33,814	30,800
Capital expenditures	647	33	825	1,258
Doors [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	4,271	4,018	13,140	12,439
Depreciation, depletion and amortization	31	32	94	103
Operating (loss) income	274	151	1,068	1,087
Segment assets	7,031	6,518	7,031	6,518
Capital expenditures		2	32	37
Heating and Cooling [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	9,473	8,473	24,493	21,091
Depreciation, depletion and amortization	142	130	427	387
Operating (loss) income	692	426	994	27
Segment assets	22,286	17,762	22,286	17,762
Capital expenditures	146	52	355	163
Evaporative Cooling [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	5,658	5,686	22,656	21,490
Depreciation, depletion and amortization	123	105	369	314
Operating (loss) income	154	97	1,850	1,746
Segment assets	11,864	13,290	11,864	13,290
Capital expenditures	66	45	167	179
Corporate, Non-Segment [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	4	4	12	11
Depreciation, depletion and amortization	14	14	40	38
Operating (loss) income	(841)	(815)	(2,365)	(2,294)
Segment assets	2,635	3,431	2,635	3,431
Construction Products [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	21,030	20,203	54,554	55,965
Depreciation, depletion and amortization	361	515	1,101	1,506
Operating (loss) income	960	(6,225)	898	(6,647)
Segment assets	40,845	37,318	40,845	37,318
Capital expenditures	647	35	857	1,295
Heating Ventilation and Air Conditioning Products [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	15,131	14,159	47,149	42,581
Depreciation, depletion and amortization	265	235	796	701
Operating (loss) income	846	523	2,844	1,773
Segment assets	34,150	31,052	34,150	31,052
Capital expenditures	$ 212	$ 97	$ 522	$ 342