INDUSTRY SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2015 USD ($) item	Jun. 28, 2014 USD ($)	Jul. 04, 2015 USD ($)	Jun. 28, 2014 USD ($)	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	$ 34,865	$ 37,367	$ 65,550	$ 64,191
Depreciation, depletion and amortization	651	743	1,297	1,481
Operating (loss) income	631	1,034	412	(651)
Segment assets	72,884	71,801	72,884	71,801	$ 71,801
Capital expenditures	427	698	520	1,505
Concrete Aggregates and Construction Supplies [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	14,090	17,023	24,655	27,341
Depreciation, depletion and amortization	340	464	677	920
Operating (loss) income	(128)	225	(856)	(1,358)
Segment assets	31,931	30,800	31,931	30,800
Capital expenditures	178	602	178	1,225
Doors [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	4,681	4,525	8,869	8,421
Depreciation, depletion and amortization	32	35	63	71
Operating (loss) income	456	541	794	936
Segment assets	7,111	6,518	7,111	6,518
Capital expenditures	32	1	32	35
Heating and Cooling [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	5,874	5,694	15,020	12,618
Depreciation, depletion and amortization	143	128	285	257
Operating (loss) income	(195)	(369)	302	(399)
Segment assets	17,696	17,762	17,696	17,762
Capital expenditures	149	55	209	111
Evaporative Cooling [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	10,216	10,121	16,998	15,804
Depreciation, depletion and amortization	123	104	246	209
Operating (loss) income	1,245	1,386	1,696	1,649
Segment assets	12,733	13,290	12,733	13,290
Capital expenditures	68	40	101	134
Corporate, Non-Segment [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	4	4	8	7
Depreciation, depletion and amortization	13	12	26	24
Operating (loss) income	(747)	(749)	(1,524)	(1,479)
Segment assets	3,413	3,431	3,413	3,431
Construction Products [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	18,771	21,548	33,524	35,762
Depreciation, depletion and amortization	372	499	740	991
Operating (loss) income	328	766	(62)	(422)
Segment assets	39,042	37,318	39,042	37,318
Capital expenditures	210	603	210	1,260
Heating Ventilation and Air Conditioning Products [Member]
INDUSTRY SEGMENT INFORMATION
Revenues from external customers	16,090	15,815	32,018	28,422
Depreciation, depletion and amortization	266	232	531	466
Operating (loss) income	1,050	1,017	1,998	1,250
Segment assets	30,429	31,052	30,429	31,052
Capital expenditures	$ 217	$ 95	$ 310	$ 245