Patterned Broadloom in a Live Hospital Corridor
A hospital renovation includes 240 m² of 2.2 m-wide corridor carpet, 45 m long, with two 90° turns and eight doorways. The specified material is a 3.66 m-wide patterned loop-pile broadloom with a 1.2 m pattern repeat, glue-down installation over a concrete substrate. The mechanical system is not commissioned; temperature is 21 °C and RH is 62%. The general contractor wants seams kept to a minimum and the pattern matched at every seam. A 30 m roll is available. The flooring must resist rolling loads from beds and carts and allow daily disinfection. The existing substrate has a 4 mm dip over 2 m near one doorway and adhesive residue from the old vinyl. The project manager proposes to cut the carpet into one length per corridor leg and seam at the two 90° turns to avoid waste. The installation is scheduled for three days, with the corridor remaining open at night.
1. Develop a seam and cutting plan. How many seams are unavoidable, where should they be placed, and how much material should be ordered?
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Because the roll is 3.66 m wide and the corridor is 2.2 m wide, the carpet can be cut lengthwise with the pattern running down the corridor, so no longitudinal seam is needed. The total run is 45 m, but the roll is 30 m, so at least one cross seam is unavoidable. A 1.2 m pattern repeat means each seam requires pattern-match allowance; I would add at least one full repeat plus trim allowance to the cut length. I would place the cross seam in a straight, low-traffic section away from doorways and away from the two 90° turns, not at a turn where the carpet must bend and where the seam would be worked. The project manager's proposal to seam at both turns creates two seams in high-stress locations and still leaves two pieces per leg, so it does not save material overall. I would order 45 m plus 10% waste plus a 1.2 m pattern-match allowance, approximately 51 m, and require the mill to supply consecutive dye lots. A seaming diagram should be issued before cutting, showing the seam location, pattern match, and direction of pile.
2. Should this carpet be stretch-in or glue-down? Justify the choice using the service conditions and the substrate.
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Glue-down is the better choice here. The corridor carries rolling beds and carts, which impose shear and rolling loads that can stretch or delaminate a stretch-in installation, especially at seams and turns. Glue-down transfers those loads to the substrate and gives a more dimensionally stable floor. It also avoids the need for stretcher clearance and tackless strip at every doorway, and it is easier to clean and disinfect in a health-care setting. The specification already calls for glue-down, so the decision is mainly to confirm that the substrate and adhesive are suitable: the adhesive residue and 4 mm dip near the doorway must be corrected first, and the concrete must be tested for moisture and pH. At 62% RH, the adhesive open time and working time will be longer than normal, and the uncured adhesive must be protected from traffic. Glue-down also means the concrete must be dry enough for the adhesive; if moisture exceeds the limit, the installation must stop rather than switch to a stretch-in system as a workaround.
3. What environmental and scheduling controls are needed before and during the installation, given that the corridor remains open at night?
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The carpet and adhesive should be acclimated in the building at 18–24 °C and 35–55% RH for at least 24–48 hours before installation; 62% RH is above the usual comfort range and will slow adhesive cure. I would require the mechanical system to be operating or provide temporary dehumidification and air movement, and I would record temperature and RH at the start and end of each shift. The corridor must be closed to patients and staff during adhesive work, with barriers and signage, because uncured adhesive is a slip and fume hazard. Glue-down carpet in a health-care corridor also needs a rolled surface and adequate ventilation. The three-day schedule must include time for substrate repair, adhesive cure, and seam sealing; night work means the adhesive may be exposed to cooler temperatures and higher RH, so the open time must be checked with a small test patch. The general contractor should provide a temporary route and a written occupancy plan before work starts.