Larsen GPM Gun Pointing Mortar

Technical information

Size	25kg multi-walled paper bag
Coverage	A 25 kg will cover approx 28 linear metres at a joint width of 5mm wide x 10mm deep
Joint widths	Minimum of 5mm wide
Joint depths	Up to 150mm deep
Compressive strength	40MPa
Application temperature	Use between 3℃ and 30℃
Working time	Approximately 40 minutes
Pot life	Approximately 30–40 minutes
Setting time	Circa 4 hours
Storage	Store unopened bags in a dark, cool and dry location away from damp and drafts
Shelf life	6 months

How do I prepare for using Larsen GPM?

All surfaces should be sound, clean and free from any loose dust, debris and dirt. When Larsen GPM is being used on paving, it should only be used on ridged constructions. On pointing applications where previous mortar has been raked out, please ensure that all dust and debris are removed and that your joint depths are at least 1.5 times width. All joints must be saturated with clean water, so that the water has soaked the paving, but prior to application ensure that any pooled or standing water has been removed, this can be achieved with a leaf blower.

How do I mix Larsen GPM?

Mix each 25KG bag of Larsen GPM, with 4.5-5.0 litres of clean water, in a large bucket with a paddle mixer. Mix for a minimum of 3 minutes, then allow to stand for a couple of minutes, then remix. To check that you've achieved the required stiff, but pliable mortar consistency, fill the tube of a pointing gun and shake. The mortar should hang from the nozzle if at the required consistency. Please note: do not mix more product than can be used in approximately 40 minutes, and do not remix or wet up mortar that has begun to 'go off' or set.

How do I apply Larsen GPM?

GPM can be applied to joints from 5mm up to 150mm deep. As a rule of thumb, joint depths should ideally be a minimum of of 1.5 times joint width. After filling the pointing gun with Larsen GPM mortar, place the nozzle deep into the joint and squeeze the mortar in, taking care to fill the joint from the bottom and slightly over fill the joint with mortar. Allow the mortar to slightly stiffen before tooling or striking off as required. Any GPM remaining on the face of the slabs or walling should be washed off before it has set. Please note: use of excessive water, or wash-boys to clean the face of the joints isn't recommended as a high amount of applied water can lead to staining and efflorescence. Always carry out a patch test prior to commencing your job to ensure that you are happy with the colour.